Question

How do you solve `-15=x^2+8x`?

Answer 1

Rearrange into standard form then factor to discover
`color(white)("XXX")x=-3 or x=-5`

Explanation:

`-15 = x^2+8x`

In standard form:
`x^2+8x+15=0`

Factored:
`(x+3)(x+5)=0`

`rArr x=-3 or x=-5`