Log(x^2-x+2) base 2=1+2logx.... solve for x

assuming both logs are base 2, then we have

log(x^2-x+2) = log2 + 2logx = log 2x^2
x^2-x+2 = 2x^2
x^2+x-2 = 0
(x+2)(x-1) = 0
x = 1

why not x = -2?