Grade 8 Math Unit 2 Assessment

Three students Anne, Barry, and Carol were walking home from school. The coordinates of their houses are given below.

Anne's House = (-1, 2)

Barry's House = (4, 2)

Carol's House = (-1, -3)

What is the equation of the line to get from Barry's house to Carol's house?

• y = 2x + 1

• y = x - 2

• y = -2x + 1

• y = x + 2

During a snowstorm, snow falls at a constant rate and is recorded by a meteorologist. The data is plotted on the graph. Which equation models the relationship between the number of hours, x, of the snowstorm, and the number of inches of snow, y, on the ground?

• y = 3x + 3

• y = ⅓x + 3

• y = 3x + 18

• y = ⅓x + 18

Ben had $100 in his savings account. He adds $5.00 a week to his savings as shown in the graph. According to this graph, how much money does he have in his savings account after 8 weeks?

• $40

• $135

• $140

• $145

Alex gathered the following data about her classmates: She created ordered pairs, (Height, Weight), from the data and found they defined a function. Which of the following actions would cause Alex's set of ordered pairs to no longer define a function?

• Adding data from a student who is 161 cm tall and weighs 63 kg.

• Adding data from a student who is 154 cm tall and weighs 69 kg.

• Converting the measurements from metric units to inches and pounds.

• Plotting the ordered pairs on a coordinate grid.

A company makes a profit based on the number of cases of candy it sells. The coordinate grid below shows the relationship between the number of cases sold and the amount of profit. Which statement best describes the function?

• The function is linear and it decreases continuously.

• The function is linear and it increases continuously.

• The function is non-linear and it decreases continuously.

• The function is non-linear and it increases continuously.

A construction company pours concrete at a constant rate to make a sidewalk. There are 1,054 cubic feet of concrete available, and 6.2 cubic feet of concrete is poured each minute. The equation and graph below show the total volume, in cubic feet, of concrete remaining t minutes after the construction company begins to pour the concrete.

C(t) = 1,054 - 6.2t

Which statement BEST describes the domain of function C(t)?

• The domain of C(t) is [0, 1,054] because the company can pour up to 1,054 cubic feet of concrete.

• The domain of C(t) is (-∞, ∞) because the company can pour concrete for any number of minutes.

• The domain of C(t) is [0, 170] because the company can pour concrete for up to 170 minutes.

• The domain of C(t) is [170, 1,054] because the company can pour 1,054 cubic feet of concrete for 170 minutes.

Limousine Company P charges a rental fee plus an additional hourly rate. The equation y = 50 + 30x shows the total cost, y, of renting the limousine, and the x represents the hours. The cost to rent a limousine from Company R is shown in the table. Which statement is true?

• Company P charges $25 more for its rental fee compared to Company R.

• Company R charges a higher rental fee, but a cheaper hourly rate to rent a limousine.

• Company P has a lower hourly rate than Company R.

• Company R charges less money for 1 hour of service compared to Company P.

Sarah & Mia babysit for 6 hours. They want to compare the amount of money they got paid per hour. The dollar amount, d, and the hours, h, are described for each of them below. Which person earns more money per hour?

• Sarah, $15 per hour.

• Mia, $5 per hour

• Mia & Sarah both make the same amount of money per hour.

• Sarah, $5 per hour.

The table shows how the amount of birdseed in a bird feeder changes over time. Which equation describes the relationship between the time in days (t) and the amount in ounces (A)?

• A = 16 − 0.6t

• A = 16 − 0.3t

• A = 16 − 3t

• A = 16 − 6t

A weightlifter is using a weightlifting bar that weighs 45 pounds. If x represents the amount of weight that the weightlifter puts on the bar and y represents the total amount that the weightlifter lifts, with the weight of the bar included, which of these functions models this situation, and why?

• y = x − 45, because the rate of change of the function should be 1 and the initial value should be 0

• y = x − 45, because the rate of change of the function should be 1 and the initial value should be −45

• y = x + 45, because the rate of change of the function should be 1 and the initial value should be 45

• y = x + 45, because the rate of change of the function should be 45 and the initial value should be 1