Question

Use the quadratic formula to solve the following quadratic equation:

x2+2x−8=0


(1 point)
Responses

x=−2, x=4

x=−2, x=4


x=−10, x=8

x=−10, x=8


x=10, x=−8

x=10, x=−8


x=2, x=−4

Answer 1

Use a = 1, b = 2, c = −8.

x = [−b ± √(b² − 4ac)] / (2a) = [−2 ± √(4 + 32)] / 2 = [−2 ± 6] / 2.

So x = (−2 + 6)/2 = 2 or x = (−2 − 6)/2 = −4.

Answer: x = 2, x = −4.