Log[2](x)+3=log[2]((x^2)-20)

Solve for x

log2(x^2-20) - log2(x) = 3
log2((x^2-20)/x) = 3
x^2 - 20 / x = 2^3
x^2 - 20 = 8x
x^2 -8x - 20 = 0
(x-10)(x+2) = 0
x = 10, -2

3 = log[2] ((x² - 20)/x)

8x = x² - 20

x² - 8x - 20 = 0

(x - 10)(x + 2) = 0

x = 10 and x = -2(reject)

Answer: x = 10