Question

The factored form of a quadratic expression is
−
2
(
x
+
4
)
(
x
−
1
)
.



What is TRUE about an equivalent expression?



A.
Equivalent Expression:
4
x
2
+
12
x
−
16

Graph: The graph of this expression would have a
y
-intercept of
(
0
,
8
)
.

B.
Equivalent Expression:
4
x
2
+
12
x
−
16

Graph: The graph of this expression would have a
y
-intercept of
(
0
,
−
16
)
.

C.
Equivalent Expression:
−
2
x
2
−
6
x
+
8

Graph: The graph of this expression would have a
y
-intercept of
(
0
,
8
)
.

D.
Equivalent Expression:
−
2
x
2
+
3
x
−
4

Graph: The graph of this expression would have a
y
-intercept of
(
0
,
−
4
)
.

Answer 1

Start by expanding:
(x + 4)(x − 1) = x^2 + 3x − 4
Multiply by −2: −2(x^2 + 3x − 4) = −2x^2 − 6x + 8.

The y-intercept is the value at x = 0, which is 8, so the point (0, 8).

Therefore C is correct.