Question

sqrt(x+64)-sqrt(x-16)=4 Solve.

I can't figure this out for the life of me.

Answer 1

1) isolate any one of the square roots

2) then square both sides

3) repeat 1)

4) repeat 2)

Answer 2

I tried that and I just got 64 and it says its wrong

Answer 3

\(x+64 = (\sqrt {x-16}+4)^2 \)

expand right side

Answer 4

(a+b)^2 = a^2+ 2ab +b^2

a= sqrt (x-16)
b=4