Question

How do you solve `sqrt(8 + 7x) - 2 = x`?

Answer 1

I found:
`x_1=4`
`x_2=-1`

Explanation:

We can rearrange and square both sides:
`sqrt(8+7x)=x+2`
squaring:
`8+7x=(x+2)^2`
`8+7x=x^2+4x+4`
`x^2-3x-4=0`
use the Quadratic Formula:
`x_(1,2)=(3+-sqrt(9+16))/2=(3+-5)/2`
giving two solutions:
`x_1=(3+5)/2=4`
`x_2=(3-5)/2=-1`