Question

What are the x-intercepts of the graph of the function below?

y = x^2 – 3x - 28

A. (-7,0) and (-4,0)
B. (7,0) and (-4,0)
C. (7,0) and (4,0)
D. (-7,0) and (4.0)

Answer 1

The x intercepts are (7,0) and (-4,0)

Explanation:

y = x^2 – 3x - 28

Set y=0

0 = x^2 – 3x - 28

Factor. What 2 numbers multiply to -28 and add to -3

-7*4 = -28

-7+4 = -3

0 = (x-7)(x+4)

Using the zero product property

0 = (x-7) 0 = x+4

x=7 x = -4

The x intercepts are (7,0) and (-4,0)