Question

What are the solutions to x2 8x 7 = 0? x = –8 and x = –7 x = –7 and x = –1 x = 1 and x = 7 x = 7 and x = 8?

Answer 1

We want to solve
x² + 8x + 7 = 0

Factorize the left side.
x² + 8x + 7 = (x + 1)(x + 7)

Therefore
(x + 1)(x + 7) = 0
When (x + 1) = 0, obtain x = -1.
When (x + 7) = 0, obtain x = -7.

The solutions are x = -1 and x = -7

Answer: x = -7 and x = -1.