a. y = x + 4, y - x = -4 => y = x + 4, y = x - 4. These lines are parallel and distinct, so no solution.
b. 2y = 2x + 8, -2x = 2y - 8 => y = x + 4, -2x = 2y -8 => y = -x + 4. The second Equation can be re-arranged as y= -x + 4, has a solution. No Solution.
c. y = 1/2 x + 6, 2x + 5 = y => y = 1/2 x + 6, 2x + 5 = y . Subsitute the second equation for y : 2x+ 5 = 1/2 x + 6 => (3/2) x= 1, has a solution.
d. y = 4x + 1, y - 1 = 4x => y = 4x + 1, y = 4x + 1: Equations are the same, has a solution, infinitely many solutions.
Answer: a. y = x + 4, y - x = -4
Question 15
Problem: Venn diagram problem about people wearing blue or red shirts. Find the missing value.
Information: Total people = 30. From the diagram determine who wears only blue, only red, or both.
Analysis: Let x be the missing value (people who wear only red). Then, the sum of all sections of the Venn diagram should equal 30.
Answer: The missing value is 7.
Question 16
Problem: Distance between Kensington and Greenwich on a map.
Analysis: Based on the map (not provided), determine the scale and measure the distance.
Answer: 20 \sqrt{5} miles.
Question 17
Problem: Calculate the commission earned on a $4450 sale with a 3% commission rate.
Solution: Commission=0.03×4450=133.50
Answer: $133.50
Question 18
Problem: Given f(x)=x2+1 and domain D = {-2, -1, 0, 1, 3}, find the range R.
Solution:
f(−2)=(−2)2+1=4+1=5
f(−1)=(−1)2+1=1+1=2
f(0)=(0)2+1=0+1=1
f(1)=(1)2+1=1+1=2
f(3)=(3)2+1=9+1=10
Range: R = {5, 2, 1, 2, 10}
Question 19
Problem: Solve y+w−43z=0 for z.
Solution: 43z=y+w⇒z=34(y+w)
Question 20
Problem: Gloria earns 1.5 times her normal pay for overtime (over 40 hours). She worked 47 hours and earned $489.85. Given 40p+7(1.5p)=489.85, find p.
Problem: Determine if the line is positive, negative, zero or undefined
Answer: The slope is undefined.
Question 22
Problem: Given A=a,b,d,f,g, U=letters of the alphabet, and A∩B=b,d, which could be set B?
Analysis: B must contain b and d, and can contain other elements from U.
Answer: B = {b, d, k}
Question 23
Problem: Leah scored p points in the first half, and in the second half, she scored 3 more than 1/2 the points she scored in the first half. Altogether she scored 21 points. Given p+(21p+3)=21, find p.
Solution: p+21p+3=21⇒23p=18⇒p=32×18=12
Answer: Leah scored 12 points in the first half.
Question 24
Problem: Subtract (6a2+3a)−(4a2+2a).
Solution: 6a2+3a−4a2−2a=(6a2−4a2)+(3a−2a)=2a2+a
Answer:2a2+a
Question 25
Problem: Find the equation of the line with x-intercept = -2 and y-intercept = -4.
Analysis: The line passes through (-2, 0) and (0, -4).
Slope: m = (-4 - 0) / (0 - (-2)) = -4 / 2 = -2
Equation: y = -2x - 4
Question 26
Problem: Janell has 5 gallons of paint. After painting 800 square feet, she has 3 gallons left. Find the equation of the linear function and interpret the slope.
Analysis: The points are (0, 5) and (800, 3) [ (sq ft, gallons)]
Slope: m = (3-5)/(800-0) = -2/800 = -1/400
Equation: y = (-1/400)x + 5
Interpretation: For every square foot painted, 1/400 th of a gallon is used
Answer: y = (-1/400)x + 5 slope = -1/400; this means that for every square foot painted, 1/400 gallons of paint is used.
Question 27
Problem: Which expression is NOT equivalent to the other expressions? a. (4x^2y)^2 c. 16x^4y^2 b. 4x^4y^2 d. 4^2x^4y^2
Solution: Let's check the options.
(4x^2y)^2 = 16x^4y^2
b. 4x^4y^2
c. 16x^4y^2
d. 4^2 x^4 y^2 = 16x^4y^2. Since expression b is different, that is answer.
Answer: b. 4x^4y^2
Question 28
Problem: The height of a ball is modeled by y=−16x2+72x, where x is the time in seconds. How long is the ball in the air?
Solution: The ball is in the air until y = 0.
0=−16x2+72x=x(−16x+72)=0
x=0 , -16x + 72 = 0 => x = 72/16 = 9/2 = 4.5
Answer: 4.5 s
Question 29
Problem: Venn diagram for sets A and B. What is the intersection? Set A: factors of 9 Set B: factors of 12
Solution: A = {1, 3, 9}, B = {1, 2, 3, 4, 6, 12}
Intersection:A∩B=1,3
Answer: {1, 3}
Question 30
Problem: Factor the expression p2−40
Since 40 is not a perfect square, we cannot factor the expression.
Problem: For f(x) = 24 - 2x, find f(2) and find x such that f(x)=10
Solution: f(2)=24−2∗2=20 10 = 24 - 2x=> -14 = -2x
Answer: 20; 7
Question 36
Problem: If you graph y=x2−6x+9 the y-intercept of the graph of the equation is
Solution:
The y-intercept is the value of y when x= 0 substitute 0 for x: y=02−6(0)+9
Answer: 9
Question 37
Problem: Reserved tickets cost $20 each and General admission tickets cost $12 each. Total $900 sold. 20x+12y = 900.
Analysis:
Examine the graph and find the equation represented and the y intercept of graph
Answer: Need Graph to solve
Question 38
Problem: Give the domain and range of the relation
Analysis:
Based on the graph determine the domain (x values) and range (y values)
Answer: Need Graph to solve
Question 39
Problem: Solve x2−7x−8=0 by factoring
Solution:
x^2 -7x - 8 = 0 => (x-8)(x+1) = 0 So we get x=8orx=−1
Answer:x=−1orx=8
Question 40
Problem: Which of the following graph shows the equation y+1=2(x−1)
Analysis:
Simplify the equation and analyze graph to find this equation.
Answer: Equation y+1 = 2(x-1) => y = 2x -3
Question 41
Problem: The scatter plot shows the relationship between the weekly total sales ($) and the number of different rug designs a rug store has. Based on this relationship, use the line of best fit to predict what the total sales will be when the store has 110 different rug designs.
Analysis:
Determine the liner of best fit to show the relationship between the two variables and use this line to predict sales amount
Answer: Need graph to solve this.
Question 42
Problem: Factor x2−16
Solution:
Difference of the two squares: x2−16=(x+4)(x−4)
Answer:(x+4)(x−4)
Question 43
Problem: Factor x2−6x−16
Solution: x2−6x−16=(x+2)(x−8)
Answer:(x+2)(x−8)
Question 44
Problem: Solve A=21(b+c)h for c
Solution:
2A = (b+c)h => 2A/h = b + c => c = 2A/h - b
Answer:c=h2A−b
Question 45
Problem: The ratio of boys to girls in a class is 2:3. If there are 18 girls in the class, how many boys are there?
Solution:
\frac{boys}{girls} = \frac{2}{3} => boys = \frac{2}{3} * 18
Answer: 12
Question 46
Problem: Solve the system of equations
2x + 3y = 4 and 3x - 3y = -9
Solution: add the two equations to eliminate for y:
5x = -5 => so x = -1 now solve for y 2(-1) + 3y = 4.
Answer: (-1, 2)
Question 47
Problem: Use the zero product property to solve equation (x=3)(x-2) = 14
Solution: Do not equate (x+3)=14 and (x-2) = 14
Rewrite the equation and multiply terms:(x+3)(x-2) = 14 = x^2 + x -6 = 14 set to 0: x^2+x -20 = 0
Problem: Which of the following is the solution to this inequality? 3(5 + 2n) ≥ 7 + 10n
Solution:
15 + 6n ≥ 7 + 10n => 8 ≥ 4n => n ≤ 2
Answer: n ≤ 2
Question 50
Problem: Multiply (x+7)(x-7)
Solution: (x+7)(x−7)=x2−49
Answer: x^2 - 49
Question 51
Problem: U is the set of natural numbers less than 8. G is the set of even integers less than 10. Which is the complement of set G in universe U?
Solution:
U = {1, 2, 3, 4, 5, 6, 7}, G = {2, 4, 6, 8}. Find all the values of U that are not in G.
Answer: {1, 3, 5, 7}
Question 52
Problem: Simplify the quotient 1215
Solution: 1215=215
Answer:215
Question 53
Problem: Graph -2x + 4y = 4 for the domain D: {–8, –4, 0, 4, 8}.
Solution: Graph and evaluate for D values
Answer: requires the graph
Question 54
Problem: Determine whether the pairing is a function. If it is a function, describe the rule that relates the input value to the output value. input -3 -1 0 1 3 output 0 2 3 4 6
Answer: The pairing is: The pairing is a function. The rule is “input value plus 3.”
Question 55
Problem: The values in the table show a linear relationship. Find the slope. x −4 2 8 14 y 10 7 4 1