Unit Test — Unit test Answers

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A quadratic equation has zero real number solutions. Which could be the discriminant value associated with this equation?

A
–5
B
0
C
1
D
6
2
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Doug bought a new car for $25,000. He estimates his car will depreciate, or lose value, at a rate of 20% per year. The value of his car is modeled by the equation V = P(1 – r)t, where V is the value of the car, P is the price he paid, r is the annual rate of depreciation, and t is the number of years he has owned the car. According to the model, what will be the approximate value of his car after years?

Question illustration
A
$2,500
B
$9,159
C
$22,827
D
$23,791
3

Mischa wrote the quadratic equation 0=-x2+4x-7 in standard form. If a = -1, what is the value of c in her equation?

A
c=-7
B
c=-1
C
c=4
D
c=7
4

Which expression is equivalent to ?

Question illustration
A
Negative 4 x Superscript 4 Baseline y Superscript 6
Option A
B
Negative 8 x Superscript 4 Baseline y Superscript 6
Option B
C
StartFraction 4 x Superscript 4 Baseline Over y Superscript 6 EndFraction
Option C
D
StartFraction 8 x Superscript 4 Baseline Over y Superscript 6 Baseline EndFraction
Option D
5

The equation shows the relationship between a planet’s orbital period, T, and the planet’s mean distance from the sun, A, in astronomical units, AU. If planet Y is k times the mean distance from the sun as planet X, by what factor is the orbital period increased?

Question illustration
A
k Superscript one-third
Option A
B
k Superscript one-half
Option B
C
k Superscript two-thirds
Option C
D
k Superscript three-halves
Option D
6

Which is the graph of a quadratic equation that has a negative discriminant?

A
On a coordinate plane, a parabola opens down. It goes through (negative 4, negative 4), has a vertex at (negative 2, 0), and goes through (0, negative 4).
Option A
B
On a coordinate plane, a parabola opens down. It goes through (negative 4, negative 4), has a vertex at (negative 2, 0), and goes through (0, negative 4).
Option B
C
On a coordinate plane, a parabola opens up. It goes through (negative 4, 4), has a vertex at (negative 2, 0), and goes through (0, 4).
Option C
D
On a coordinate plane, a parabola opens up. It goes through (negative 4, 8), has a vertex at (negative 2, 4), and goes through (0, 8).
Option D
7

What is the value of the discriminant, b2 − 4ac, for the quadratic equation 0 = −2x2 − 3x + 8, and what does it mean about the number of real solutions the equation has?

A
The discriminant is −55, so the equation has 2 real solutions.
B
The discriminant is −55, so the equation has no real solutions.
C
The discriminant is 73, so the equation has 2 real solutions.
D
The discriminant is 73, so the equation has no real solutions.
8

A quadratic equation of the form 0 = ax2 + bx + c has one real number solution. Which could be the equation?

A
0 = 2x2 – 4x + 1
B
0 = 2x2 – 5x + 3
C
0 = –2x2 – 4x – 2
D
0 = –2x2 – 3x – 1
9

Which expression is equivalent to ?

Question illustration
A
StartFraction x Superscript one-half baseline Over y z squared EndFraction
Option A
B
StartFraction x Superscript one-half baseline Over y Superscript one-fourth Baseline z squared EndFraction
Option B
C
StartFraction y Superscript one-half Baseline Over x z squared EndFraction
Option C
D
StartFraction x z squared Over y Superscript one-half EndFraction
Option D
10

Which equation has an a-value of –2, a b-value of 1, and a c-value of 3?

A
0 = –2x2 + x + 3
B
0 = 2x2 + x + 3
C
0 = –2x2 + 3
D
0 = 2x2 – x + 3
11

Nathan has a rectangular plot of grass in his backyard that has dimensions of meters in width and meters in length. What is the total area of the plot of grass? Recall that the area of a rectangle is the width multiplied by the length.

Question illustration
A
square meters
Option A
B
square meters
Option B
C
square meters
Option C
D
square meters
Option D
12

Between which two ordered pairs does the graph of f(x) = x2 + x – 9 cross the negative x-axis?Quadratic formula: x =

Question illustration
A
(–6, 0) and (–5, 0)
B
(–4, 0) and (–3, 0)
C
(–3, 0) and (–2, 0)
D
(–2, 0) and (–1, 0)
13

Combine these radicals.

Question illustration
A
Option
Option A
B
Option
Option B
C
Option
Option C
D
Option
Option D
14

What is the value of the discriminant of the quadratic equation −2x2 = −8x + 8, and what does its value mean about the number of real number solutions the equation has?

A
The discriminant is equal to 0, which means the equation has no real number solutions.
B
The discriminant is equal to 0, which means the equation has one real number solution.
C
The discriminant is equal to 128, which means the equation has no real number solutions.
D
The discriminant is equal to 128, which means the equation has two real number solutions.
15

Sandra bought 120 square feet of carpet for a room in her new house. If the room is square, what is the length of each side of the room?Recall that the area of a square is calculated by l2, where l is the length of one side.

A
feet
Option A
B
feet
Option B
C
feet
Option C
D
feet
Option D

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