Algebra 4

7 September 2022
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question
Gina, Sam, and Robby all rented movies from the same video store. They each rented some dramas, comedies, and documentaries. Gina rented 11 movies total. Sam rented twice as many dramas, three times as many comedies, and twice as many documentaries as Gina. He rented 27 movies total. If Robby rented 19 movies total with the same number of dramas, twice as many comedies, and twice as many documentaries as Gina, how many movies of each type did Gina rent?
answer
3 dramas, 5 comedies, and 3 documentaries WORK ON PAPER
question
Solve 5x + 2y = 7 10x + 4y = 14
answer
Infinitely many solutions
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Samantha is going on vacation for the summer and is trying to choose between two different plans. The first plan costs $450 for 3 days at a hotel and 2 days at an amusement park. The second plan offers 5 days at the same hotel and 3 days at the amusement park for $700. The cost of 1 day at the hotel and the amusement park is the same under both plans. How much does a 1-day trip to the amusement park cost?
answer
$150 WORK ON PAPER
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In the below system, solve for y in the first equation. x โˆ’ 3y = โˆ’6 2x โˆ’ 7y = 10
answer
(1/3)x + 2 WORK ON PAPER
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Solve 3x โˆ’ 5y = 17 9x โˆ’ 15y = โˆ’4
answer
No solutions
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What is the value of y in the solution to the following system of equations? 5x โˆ’ 3y = โˆ’3 2x โˆ’ 6y = โˆ’6
answer
1
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Use the substitution method to solve the following system of equations: 4x โˆ’ y = 3 7x โˆ’ 9y = โˆ’2
answer
4x = y + 3 ---> y = 4x - 3 7x - 9(4x-3) = -2 ---> 7x - 36x + 27 = -2 -29x = -29 x = 1 (1, 1)
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Solve 5x โˆ’ 6y = โˆ’38 3x + 4y = 0
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(โˆ’4, 3)
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Solve 7x โˆ’ 2y = โˆ’3 14x + y = 14
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(5/7, 4)
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Jonathan uploaded some original songs and also some pictures. Alissa uploaded four times as many songs, but only uploaded twice as many pictures. Jonathan uploaded 11 items while Alissa uploaded 24. How many songs did Jonathan upload?
answer
1
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Solve the following system using elimination: 2x - 2y = 10 3x + 2y = 20
answer
(6, 1)
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Solve the following system using elimination: 4x - y = 5 x + 5y = -4
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(1, -1)
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Solve the following system using elimination: 3x + 5y = 1 4x + 2y = -8
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(-3, 2)
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Solve the following system using substitution: x - 4y = 1 3x - y = 14
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(5, 1)
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Solve the following system using substitution: 2x - 4y = 6 3x + 9y = 9
answer
(3, 0)
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Solve the following system: y = xยฒ + 2x - 3 -3x + y = -1
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(2, 5), (-1, 4)
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Solve the following system: xยฒ+yยฒ = 17 y = x - 3
answer
(4, 1) , (-1, -4)
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What is the value of y in the solution to the following system of equations? 5x โˆ’ 3y = โˆ’11 2x โˆ’ 6y = โˆ’14
answer
5x โˆ’ 3y = โˆ’11 x2 2x โˆ’ 6y = โˆ’14 x2 (-5) 10x - 6y = -22 -10x + 30y - 70 ------------------ 30y - 6y = 70 - 22 24y = 48 y = 2
question
Mark, Jessica, and Nate each downloaded music from the same website. Mark downloaded 10 songs in total consisting of pop, rock, and hip hop. Jessica downloaded five times as many pop songs, twice as many rock, and three times as many hip hop songs as Mark. She downloaded 28 songs total. If Nate downloaded 20 songs total with three times as many pop songs, three times as many rock songs, and the same number of hip hop songs as Mark, how many songs of each type did Mark download?
answer
Mark downloaded 1 pop songs, 4 rock songs, and 5 hip hop songs.
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What is one of the solutions to the following system of equations? yยฒ + xยฒ = 65 y + x = 7
answer
(8, โˆ’1)
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Which system of equations is represented by the graph? a line is graphed through points negative (6, 9) and (-5, 3). It intersects a parabola that opens up at these two points. Courtesy of Texas Instruments
answer
y = xยฒ + 5x + 3 6x + y = โˆ’27
question
What is the solution to the following system of equations? y = โˆ’xยฒ โˆ’ 5x โˆ’ 4 y = โˆ’xยฒ + 9x โˆ’ 18
answer
(1, โˆ’10)
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What are the solutions to the following system of equations? y = xยฒ + 12x + 30 8x โˆ’ y = 10
answer
No real solutions
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Which system of equations is represented by the graph? A Rational graph with asymptotes of x equals negative 2 and y equals 1. Linear graph intersects it at (-1, -5) and (4, 0).
answer
y = x - 4/ x + 2 y = x โˆ’ 4
question
What are the solutions to the following system of equations? y = x2 + 3x โˆ’ 7 3x โˆ’ y = โˆ’2
answer
y = 3x + 2 3x + 2 = x^2 + 3x - 7 x^2 -9 = 0 x^2 = 9 x1 = 3 x2 = -3 y1 = 3*3+2 = 11 y2 = -3*3 + 2 = -7 (3,11) and (-3,-7)
question
What is the solution to the following system of equations? y = x2 + 10x + 11 y = x2 + x โˆ’ 7
answer
y = y x^2+10x+ 11 = x^2+x -7 10x-x = -7-11 9x=-18 x=-2 y = (-2)^2+(-2)-7 = 4-2-7 =-5 (-2,-5)
question
Solve the system 2x + 3y = 3 and 3x โˆ’ 2y = 11 by using graph paper or graphing technology. What is the solution to the system?
answer
two linear equations 2x + 3y = 3 and 3x - 2y = 11 and is asked for the solution of the system of equations. In this case, we can eliminate x by multiplying the second equation by -2/3. This leaves y to be equal to -1 and x from the first eqn to be equal to 3. (3, -1)
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Solve the system y = 2x + 6 and 3y = 6x + 18 by using graph paper or graphing technology. What is the solution to the system?
answer
Infinite Solutions
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What is the graph of the system y = โˆ’2x + 3 and 2x + 4y = 8?
answer
Line through point (0,3) and (-1,1). Line through (0,2) and (4,0) The one that resembles this the most is letter C
question
At the end of April, Mandy told Bill that she has read 16 books this year and reads 2 books each month. Bill wants to catch up to Mandy. He tracks his book reading with a table on his door. Using his table below, what month will Bill have read the same amount of books as Mandy?
answer
December
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What equation is solved by the graphed systems of equations? (7,25)
answer
3x + 4 = 5x โˆ’ 10
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Solve the following system of equations by substitution and select the correct answer below: 4x โˆ’ 6y = 28 8x โˆ’ 4y = 24
answer
4x - 6y = 28......(1) 8x - 4y = 24......(2) Using Equation (2) 8x - 4y = 24 8x = 24 + 4y x = 3 + 1/2y....(2) Substituting x = 3 + 1/2y into Equation (1) 4(3 + 1/2y) - 6y = 28 12 + 2y - 6y = 28 Collect like terms: 2y - 6y = 28 - 12 -4y = 16 y = -4 Substitute y = -4 into Equation (1) 4x - 6y = 28 4x - 6(-4) = 28 4x + 24 = 28 4x = 28 - 24 4x = 4 x = 1 x = 1; y = -4
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What are the solutions to the following system of equations? Select the correct answer below. y = x2 โˆ’ 4x + 3 2x + y = 6
answer
Substitute x2โˆ’4x+3 for y into 2x+y=6 then solve for x. x=3,โˆ’1Substitute 0 for x into 2x+y=6 then solve for y. y=0Substitute 8 for x into 2x+y=6 then solve for y. y=8 The solution can be shown in both point and equation forms. Point Form: (3,0),(โˆ’1,8) Equation Form: x=3,โˆ’1 y=0,8
question
Solve the following system of equations by graphing and select the correct answer below: 2x + 6y = 20 3x โˆ’ 2y = 8
answer
2x+6y+(9x-6y)=20+24 11x=44 X=4 Y=2
question
Sherri has 23 pieces of jewelry to sell. She sells the bracelets for $2 and the necklaces for $3, and earns a total of $55. If the bracelets are represented by x and the necklaces are represented by y, which of the following systems of equations can be used to calculate the number of bracelets and necklaces sold?
answer
x = bracelets y = necklaces there are 23 of them in total (necklaces + bracelets) x + y = 23 bracelets are $2 each and necklaces are $3 each...totaling $55 2x + 3y = 55
question
Marcia can make 5 candles in an hour. Kevin can make only 4 candles in an hour, but he already has 7 completed candles. Explain to Marcia how she can use a system of equations to determine when she will have the same number of candles as Kevin. Use complete sentences.
answer
m(h)=5h that is Marcia's number of candles where she makes 5 candles per hour (h) kevin makes 4 but already did 7 so k(h)=4h+7 when will they have the same number of candles? when will m(h)=k(h) set equal 5h=4h+7 minus 4h from both sides 1h=7 answer is 7 hours the system of equation is m=5h k=4h+7 find what value of h makes m=k true answer is 7 hours
question
Mark went to an electronic store, purchased 2 CDs and 6 DVDs, and spent $156. Antonio went to the same store, bought 1 CD and 9 DVDs, and spent $210. How much does each CD sell for at the store?
answer
Let C be CD's Let D be DVD's 2C + 6D = 156 C + 9D = 210 6D = 156 - 2C 3D = 78 - C C + 9D = 210 C + 3(78 - C) = 210 C + 234 - 3C = 210 234 - 210 = 3C - C 24 = 2C 12 = C The cost of one CD is $12
question
If you were to use the substitution method to solve the following system, choose the new equation after the expression equivalent to x from the first equation is substituted into the second equation. x + 4y = โˆ’9 2x + 5y = โˆ’6
answer
x + 4y = -9 2x + 5y = -6 x = -4y - 9 plug into the 2x + 5y = -6 in place of the 'x'. 2(-4y -9) + 5y = -6
question
How can one half x โˆ’ 5 = one third x + 6 be set up as a system of equations?
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y = (1/2)(x) - 5 multiply each term by 2 to clear the fraction 2y = x - 10 y = (1/3)(x) + 6 multiply each term by 3 to clear the fraction 3y = x + 18 2y = x - 10 Rearranging 2y - x = -10 3y = x + 18 3y - x = 18
question
Solve the following system of equations: 4x + 7y โˆ’ 2z = 0 3x โˆ’ 5y + 3z = 9 3x + 6y โˆ’ z = 1
answer
[1] 4x + 7y - 2z = 0 [2] 3x - 5y + 3z = 9 [3] 3x + 6y - z = 1 Solve by Substitution : // Solve equation [3] for the variable z [3] z = 3x + 6y - 1 // Plug this in for variable z in equation [1] [1] 4x + 7y - 2โ€ข(3x+6y-1) = 0 [1] -2x - 5y = -2 // Plug this in for variable z in equation [2] [2] 3x - 5y + 3โ€ข(3x+6y-1) = 9 [2] 12x + 13y = 12 // Solve equation [2] for the variable y [2] 13y = -12x + 12 [2] y = -12x/13 + 12/13 // Plug this in for variable y in equation [1] [1] -2x - 5โ€ข(-12x/13+12/13) = -2 [1] 34x/13 = 34/13 [1] 34x = 34 // Solve equation [1] for the variable x [1] 34x = 34 [1] x = 1 // By now we know this much : x = 1 y = -12x/13+12/13 z = 3x+6y-1 // Use the x value to solve for y y = -(12/13)(1)+12/13 = 0 // Use the x and y values to solve for z z = 3(1)+6(0)-1 = 2 Solution : {x,y,z} = {1,0,2}
question
Choose the graph that matches the following system of equations: 8x + 5y = โˆ’5 7x โˆ’ 3y = 3
answer
In intercept form, the equations are .. x/(-5/8) +y/(-1) = 1 .. x/(3/7) +y/(-1) = 1 The first line has intercepts (-5/8, 0) and (0, -1). The second line has intercepts (3/7, 0) and (0, -1) In the second graph, the (blue) line with positive slope has an x-intercept greater than 1/2. Neither line matches that. The intercepts match those of the first graph.
question
How can 1/4x โˆ’ 3 = 1/2x + 8 be set up as a system of equations?
answer
4y โˆ’ x = โˆ’12 2y โˆ’ x = 16
question
Which equation does the graph of the systems of equations solve?
answer
The solution to this system is (x,y) = (2,-3) D. one half x โˆ’ 4 = โˆ’2x + 1 >>> x/2 - 4 = y...........> (2)/2 -4 = -3 >>> -2x + 1 = y ......> -2(2) +1 = -3
question
What are the solutions to the following system of equations? y = x2 + 3x โˆ’ 7 3x โˆ’ y = โˆ’2
answer
y = 3x + 2 after that we get: 3x + 2 = x^2 + 3x - 7 x^2 -9 = 0 x^2 = 9 x1 = 3 x2 = -3 y1 = 3*3+2 = 11 y2 = -3*3 + 2 = -7 we get pairs: (3,11) and (-3,-7)
question
What is the solution to the following system of equations? y = x2 + 10x + 11 y = x2 + x โˆ’ 7
answer
y=x^2+10x+11 y=x^2+x-7 therefore, x^2+10x+11=x^2+x-7 x^+10x+11-x^2-x+7=0 9x+18=0 x=-2 y=(-2)^2+10(-2)+11= -5
question
What is one of the solutions to the following system of equations? y2 + x2 = 53 y โˆ’ x = 5
answer
Answer: B. (โˆ’7, โˆ’2) SOLVINGS y^2 + x^2 = 53 ..... (Equation I) y โˆ’ x = 5 ..... (Equation II) Make y the subject of equation II y = x + 5 ..... (Equation III) Substitute (x + 5) for the value of y in Equation I โˆด (x + 5)^2 + x^2 = 53 x^2 + 10x + 25 + x^2 = 53 2 x^2 + 10x + 25 = 53 2 x^2 + 10x + 25 - 53 = 0 2 x^2 + 10x - 28 = 0 ..... (Equation IV) Factor 2 out of equation IV; 2 (x^2 + 5x - 14) = 0 ..... (Equation V) Divide both sides of equation V by 0 โˆด x^2 + 5x - 14 = 0 x^2 + (7x - 2x) - 14 = 0 x^2 + 7x - 2x - 14 = 0 ..... (Equation VI) Divide Equation VI into two groups (x^2 + 7x and - 2x - 14) x + 7 is a common factor in both groups Factor out x + 7 in Equation VI โˆด x(x + 7) - 2(x +7) = 0 (x - 2) (x +7) = 0 โˆด x - 2 = 0 OR x + 7 = 0 x = 2 OR x = -7 x = 2, -7 If x = 2 Substitute 2 for the value of x in equation II y โˆ’ x = 5 y - 2 = 5 y = 5 +2 y = 7(x =2, y =7) ... Not included in the options If x = -7 Substitute -7 for the value of x in equation II y โˆ’ x = 5 y - (-7) = 5 y + 7 = 5 y = 5 - 7 y = -2(x = -7, y = -2) .... This tally with option B
question
Which system of equations is represented by the graph? (4,0) (-1,-5)
answer
y = x - 4/ x + 2 y = x โˆ’ 4
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Which system of equations is represented by the graph? (6, 9) (-5, 3).
answer
y = xยฒ + 5x + 3 6x + y = โˆ’27
question
Solve the following system of equations by substitution and select the correct answer below: 6x โˆ’ 4y = 36 2x โˆ’ 8y = 32
answer
6x - 4y = 36 2x - 8y = 32 ( multiply by '-3'( . Hence 6x - 4y = 36 -6x + 24y = -96 Add 20y = -60 y = -3 Hence 6x - 4(-3) = 36 6x + 12 = 36 6x = 24 x = 4 Hence Answer is (4, -3).
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What are the solutions to the following system of equations? Select the correct answer below. y = x2 โˆ’ 2x + 4 8x + y = 20
answer
(2, 4) and (โˆ’8, 84)
question
Brad can make 4 key chains in an hour. Velma can make only 3 key chains in an hour, but she already has 6 completed key chains. Explain to Brad how he can use a system of equations to determine when he will have the same number of key chains as Velma. Use complete sentences.
answer
let t= time in hours, b= no of keychains made by brad, v=no of keychains made by velma. b=4t v=3t+6 equate b and v to get time t when they have equal keychains. so, 4t=3t+6 so, t=6 hours
question
Kara has 21 collectible buttons to sell. She sells the small buttons for $3 and the large buttons for $4, and earns a total of $68. If the small buttons are represented by x and the large buttons are represented by y which of the following systems of equations can be used to calculate the number of large and small buttons sold.
answer
x+y=21 3x+4y=68
question
Solve the following system of equations by graphing and select the correct answer below: 3x + 5y = 38 4x โˆ’ 2y = 16
answer
(6,4)
question
Amy purchased 17 pencils and 18 pens for a fund-raiser at school and spent $61.50. Jocelyn purchased 10 pencils and 21 pens and spent $57. How much does each pencil cost?
answer
Let, pencils be "x" pens be "y" According to the question, 17x + 18y = 61.50 ----------> equation (1) 10x + 21y = 57 -----------------> equation (2) Now, Taking equation (1), 17x + 18y = 61.50 18y = 61.50 - 17x y = (61.50 - 17x ) / 18 -----> equation (3) Now, substituting the value of "y" in equation (2), we get, 10x+21 (61.50-17x/18)=57 10x+7 (61.50-17x/6)=57 10x+ 430.50-119x/6=57 10x*6/6 430.50-119x/6=57 60x/6+ 430.50-119x/6=57 430.50+60x-119x/6=57 430.50-59x=342 59x=430.50-342 x=88.5/59 x=1.5 So, Each pencil costs $1.5
question
If you were to use the substitution method to solve the following system, choose the new equation after the expression equivalent to y from the first equation is substituted into the second equation. 6x โˆ’ y = 1 4x โˆ’ 3y = โˆ’11
answer
6x - y = 1 6x - y - 1 = 0 6x - 1 = y Substituting we get 4x - 3(6x - 1) = -11
question
Solve the following system of equations: 2x + 3y โˆ’ z = 1 3x + y + 2z = 12 x + 2y โˆ’ 3z = โˆ’5
answer
(3,-1,2)
question
How can 1/3x โˆ’ 2 = 1/4x + 11 be set up as a system of equations?
answer
1/3x - 2 = 1/4x + 11....it looks to me like one y was subbed in for another... ur 2 equations are : y = 1/3x - 2 and y = 1/4x + 11...but we need them in standard form... y = 1/3x - 2 -1/3x + y = -2 ..multiply by 3 -x + 3y = -6.....or 3y - x = -6 <== y = 1/4x + 11 -1/4x + y = 11 ...multiply by 4 -x + 4y = 44 or 4y - x = 44
question
What exponential function represents the data in the table?
answer
f(x) = 4x
question
Solve 8 = 2x + 4.
answer
x=-1
question
Solve 81x = 27x + 2
answer
x=6
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Solve 1 / 36 = 6xโˆ’3
answer
x=1
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Solve (square root of 7) ^6 x = 49^xโˆ’6
answer
x=-12
question
If $360 is invested at an interest rate of 4% per year and is compounded quarterly, how much will the investment be worth in 18 years?
answer
$736.96
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If $535 is invested at an interest rate of 6% per year and is compounded continuously, how much will the investment be worth in 10 years?
answer
$974.83
question
A bacteria culture begins with 4 bacteria which double in size every hour. How many bacteria exist in the culture after 8 hours?
answer
1,024
question
A jet ski depreciates at 11% of its original value each year. If the jet ski was $8,000 at its time of purchase, what is the value of the jet ski after 5 years?
answer
$4,467.25
question
If a hospital patient is given 50 milligrams of medicine which leaves the bloodstream at 10% per hour, how many milligrams of medicine will remain in the system after 6 hours? Use the function A(t) = Ie^rt.
answer
27.44 mg
question
What type of solutions do the methods for solving systems of equations find and how does this relate to setting the equations equal to each other?
answer
A system of equations is a set of two or more equations that share two or more unknowns. The solutions to a system of equations are the total amounts that make all of the equations true, as well as the locations where the graphs of the equations intersect. You can determine a system of linear equations through graphing, linear combination and substitution. Systems of nonlinear functions, for example, quadratic or exponential equations, can be managed with the equivalent methods.
question
The Mathalot Company makes and sells textbooks. They have one linear function that represents the cost of producing textbooks and another linear function that models how much income they get from those textbooks. Describe the key features that would determine if these linear functions ever intercepted.
answer
If two lines have the same slope, they are parallel and will never intercept. If they don't have the same slope, they will intercept.
question
Solve the following system of equations and show all work. y = 2x2 y = โˆ’3x โˆ’1
answer
Since both right sides of each equation is equal to y, we can set them equal to each other. 2xยฒ = -3x - 1 Let's get everything on the left side... 2xยฒ + 3x + 1 = 0 Let's solve this quadratic by splitting the middle... We want two #'s that add up to 3 and multiply to 2. (2ร—1) These are 2 and 1. Let's split the middle into 2x and x. 2xยฒ + 2x + x + 1 = 0 Factor the first and last two terms. 2x(x+1)+1(x+1) = 0 (2x+1)(x+1) = 0 If any value of x makes either factor evaluate to 0, it is a solution. 2x + 1 = 0 โ‡’ 2x = -1 โ‡’ x = -1/2 โ‡’ y = 2(-1/2)ยฒ = 2(1/4) = 1/2 x + 1 = 0 โ‡’ x = -1 โ‡’ y = 2(-1)ยฒ = 2(1) = 2 Our solutions are (-1/2, 1/2) and (-1, 2).
question
Your boss hands you the monthly data that show the number of orders coming in to and out of the warehouse. The data are in the table below. Explain to your boss, in complete sentences, the solution to this system and what the solution represents.
answer
Month No. of orders in No. of orders out January (1) 3 1 February (2) 4 3 March (3) 5 5 April (4) 6 7 Number of orders in a = number of month + 2 f(x) = x + 2. Number of orders out = 2 number of month + 1 g(x) = 2x - 1 So, in words, the numbers of orders is equal to the number of month plus 1. This represents a linear function, with slope 1 and y-intercept 2. And the numbers of orders out is also a linear function with slope 2 and y-intercept - 1.
question
Determine whether the point (1, 1) is a solution to the system of equations. Explain your reasoning in complete sentences.
answer
The solutions to the system of equations are the point of intersection of the graphs of the equations. The point of intersection of the graphs of the given equation is (0, 2). Therefore, point (1, 1) is not a solution to the system of equation.
question
How do you use properties of exponents and logarithms to rewrite functions in equivalent forms and solve equations?
answer
The exponential function of the base a, so the generic form is f (x) = a ^ x, as a positive number beside one. Every exponential function of form f (x) = a^x, act with these Properties - 1. The function applied to the zero value is always equal to 1: f (0) = a ^ 0 = 1 2. The exponential function of 1 is always equal to the base: f (1) = a ^ 1 = a. 3. The exponential function of a total is equal to the product of the use of the function on each value separately. f (m + n) = a ^ (m + n) = a ^ m ยท a ^ n = f (m) ยท f (n). 4. The exponential function of subtraction is equal to the quotient use to a quantity or number which another is to be subtracted, then divided by the application to the quantity or number to be subtracted from another: f (p - q) = a ^ (p - q) = a ^ p / a ^ q Logarithm: In the log (b), a is called the base of the logarithm and b is called an argument, with a and b positive. Consequently, the definition of logarithm is: log b = n --> a ^ n = b (a > 0, b > 0)