Question

Solve the following equation for x: -4 sqrt(x+9) = 20

Answer 1

i think this might be an extraneous solution

Answer 2

SQRT(X-8)=X-10
SQUARE BOTH SIDES
X-8=X^2-20X+100
X^2-20X-X+100+8=0
X^2-21X+108=0

(X-12)(X-9)=0
X-12=0
X=12 ANSWER
X-9=0
X=9 ANSWER.