Unit Recovery: Selected
problems 8th Grade
Subject: Mathematics
State: Colorado
Student Name:
Teacher Name:
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Copyright 2014-2015 The Achievement Network. All Rights Reserved.
CO - Unit Recovery: Selected problems 8th Grade
1 Lena paid $18.96 for 3 pounds of coffee.
(a) What is the cost per pound of this coffee?
(b) How many pounds of coffee could Lena buy for $1.00?
(c) Draw a graph in the coordinate plane of the relationship between the number of pounds
of coffee and the total cost. If you can, use technology to do this.
(d) In this situation, what is the meaning of the slope of the line you drew in part (3)?
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
2 The graphs below show the distances two cars have traveled along the freeway over a
period of several seconds. Car A is traveling 30 meters per second.
Which equation from those shown below is the best choice for describing the distance
traveled by Car B after x seconds?
A. y = 85x
C. y = 30x
B. y = 60x
D. y = 15x
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
3 Use the graph shown below to answer the question.
Which statement is not true?
A. The slope of the line is .
C. The smaller triangle and the larger
triangle shown are similar.
B. The slope of the line is - .
D. The simplified ratio of the vertical side
length to the horizontal side length of
each triangle is .
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
4 Line t and ∆ECA and ∆FDB are shown on the coordinate grid.
Which statements are true?
Select all that apply.
A. The slope of AC is equal to the slope of BC.
B. The slope of AC is equal to the slope of BD.
C. The slope of AC is equal to the slope of line t.
D. The slope of line t is equal to
.
E. The slope of line t is equal to
.
F. The slope of line t is equal to
.
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
5 Which number is equivalent to 5-1?
A. -5
C.
B. -
D. 5
6 What is the value of 20 + 2-1 + 2-2?
A. -6
C. 1
B. 2-3
D. 7
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
7 The United States exported approximately 30,000,000 metric tons of wheat over an
entire year. What is the number of metric tons of wheat written in scientific notation?
A. 3 × 104
C. 3 × 106
B. 3 × 105
D. 3 × 107
8 A dollar bill is about 3 × 10-4 inches thick. A penny is about 6 × 10-3 inches thick.
Which statement correctly compares these measurements?
A. The thickness of a dollar bill is
thickness of a penny.
the
C. The thickness of a dollar bill is 10
times the thickness of a penny.
B. The thickness of a dollar bill is
thickness of a penny.
the
D. The thickness of a dollar bill is 20
times the thickness of a penny.
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
9 The Horseshoe Nebula is about 5.0 × 103 light years away from Earth. One light year is
equal to approximately 5.9 × 1012 miles. What is the approximate distance in miles, between
Earth and the Horseshoe Nebula?
A. 2.95 × 1016
C. 10.9 × 1015
B. 2.95 × 1036
D. 10.9 × 1036
10 A computer can do 1000 operations in 4.5 × 10–6 seconds. How many operations
can be done by this computer in one hour? Express your answer in scientific
notation.
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
11 Fill in each x-value and y-value in the table below to create a relation that is not a function.
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
12 Which graph below does not represent a function of x?
A.
C.
B.
D.
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
13 The three different linear functions below are represented in three different
ways, as shown.
Which function has the greatest rate of change? Does any pair of functions have the
same rate of change? Justify your answer.
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
14 (a) Decide which of the following points are on the graph of the function y = 2x + 1:
•
•
(0, 1), (2. 5), ( , 2), (2, −1), (−1, −1), (0.5, 1)
Find 3 more points on the graph of the function.
(b) Find several points that are on the graph of the function y = 2x2 + 1. Plot the points on a
coordinate plane. Is this a linear function? Support your conclusion.,
(c) Graph both functions and list as many differences between the two functions as you
can.
15 Which is a linear function?
A. y = x2 + 4
C. y = 4x3
B. y =
D. y = x
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
16 The total cost of an order of shirts from a company consists of the cost of each shirt plus a
one-time design fee. The cost of each shirt is the same regardless of how many shirts are
ordered.
The company provides the following examples to customers to help them estimate the total
cost of an order of shirts.
•
•
50 shirts cost $349.50.
500 shirts cost $2370.
(a) Based on the examples, what is the cost of each shirt, not including the one-time design
fee? Explain how you found your answer.
(b) What is the cost of the one-time design fee? Explain how you found your answer.
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
17 Which of the following scenarios could be modeled by the equation y = 2x + 5? Circle YES
or NO for each one.
(a) There are initially 5 rabbits on the farm. Each month thereafter the number of rabbits is
2 times the number in the month before. How many rabbits are there after x months?
YES or NO
(b) Joaquin earns $2.00 for each magazine sale. Each time he sells a magazine he also gets a
five-dollar tip. How much money will he earn after selling x magazines?
YES or NO
(c) Sandy charges $2.00 an hour for babysitting. Parents are charged $5.00 if they arrive
home later than scheduled. Assuming the parents arrived late, how much money does she
earn for x hours?
YES or NO
(d) I have a sequence of integers. The first term of the sequence is 7 and the difference
between any consecutive terms is always equal to 2.
YES or NO
(e) Sneak Preview is a members-only video rental store. There is a $2.00 initiation fee and
a $5.00 per video rental fee. How much would John owe on his first visit if he becomes a
member and rents x videos?
YES or NO
(f) Andy is saving money for a new CD player. He began saving with a $5.00 gift and will
continue to save $2.00 each week. How much money will he have saved at the end of x
weeks?
YES or NO
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
18 The graph below shows Carlos’s speed on his trip to school.
Based on the graph, when is Carlos’s speed decreasing most rapidly?
A. for times between B and C
C. for times between E and F
B. for times between D and E
D. for times between H and I
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
19 Carla rode her bike to her grandmother's house. The following information describes her
trip:
•
•
•
•
•
For the first 5 minutes, Carla rode fast and then slowed down. She rode 1 mile.
For the next 15 minutes, Carla rode at a steady pace until she arrived at her
grandmother's house. She rode 3 miles.
For the next 10 minutes, Carla visited her grandmother.
For the next 5 minutes, Carla rode slowly at first but then began to ride faster.
She rode 1 mile.
For the last 10 minutes, Carla rode fast. She rode 3 miles at a steady pace.
Choose the graph that best matches this description of Carla's trip.
A.
C.
B.
D.
Mathematics
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CO - Unit Recovery: Selected problems 8th Grade
20 The scatter plot below represents the areas and populations of the towns in one
geographic region.
Which pair of words best describes the relationship between the variables in the
scatter plot?
A. Negative, linear
C. Negative, nonlinear
B. Positive, linear
D. Positive, nonlinear
Mathematics
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