Unit Test — Unit test Answers

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5

Heather is writing a quadratic function that represents a parabola that touches but does not cross the x-axis at x = –6. Which function could Heather be writing?

A
f(x) = x2 + 36x + 12
B
f(x) = x2 – 36x – 12
C
f(x) = –x2 + 12x + 36
D
f(x) = –x2 – 12x – 36
6

The first few steps in solving the quadratic equation 5x2 + 27x = 14 − 13x by completing the square are shown.5x2 + 27x = 14 − 13x5x2 + 40x = 145(x2 + 8x) = 14

A
5(x2 + 8x + 16) = 30
B
5(x2 + 8x + 16) = 94
C
5(x2 + 8x + 4) = 18
D
5(x2 + 8x + 4) = 34
7

An architect designs a diagonal path across a rectangular patio. The path is 29 meters long. The width of the patio is x meters, and the length of the path is 5 meters more than the width.

Question illustration
A
0.5(x)(x + 5) = 29
B
0.5(x)(x + 5) = 841
C
x2 + (x + 5)2 = 29
D
x2 + (x + 5)2 = 841
8

A rectangle’s length is 5 inches more than twice its width. Its area is 50 square inches. Which equation can be used to find its width, w?

A
2w(2w + 5) = 50
B
2w(w + 5) = 50
C
w(2w + 5) = 50
D
w(w + 5) = 50
9

The product of two consecutive integers is 272. Which quadratic equation can be used to find x, the smaller number?

A
x2 + 1 = 272
B
x2 − 1 = 272
C
x2 + x − 272 = 0
D
x2 + x + 272 = 0
10

Solve x2 + 6x = 7 by completing the square. Which is the solution set of the equation?

A
{–7, 1}
B
(negative 3 minus StartRoot 10 EndRoot comma negative 3 + StartRoot 10 EndRoot)
Option B
C
(3 minus StartRoot 10 EndRoot comma negative 3 + StartRoot 10 EndRoot)
Option C
D
{1, 7}
11

Two sandboxes with the same area are shown.The equation represents the area of Sandbox 2 in terms of its width.

Question illustration
A
2.72 meters
B
3.06 meters
C
9.16 meters
D
10.18 meters
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)

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