# How do you solve x =sqrt { -3x+40} and find any extraneous solutions?

Jan 24, 2017

x=5, -8

#### Explanation:

Square both sides to have ${x}^{2} = - 3 x + 40$

Or, ${x}^{2} + 3 x - 40 = 0$

This can be factorised as (x+8)(x-5)=0

Solution is therefore x=5 , -8

There are no extraneous solution