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

1 Answer
Gió
Feb 21, 2016

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

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