log(a)(2x^2-7)=2log(a)(x-1)
loga(2x^2-7) = 2loga(x-1)
loga(2x^2-7) = loga(x-1)^2
2x^2 - 7 = (x - 1)^2
2x^2 - 7 = x^2 - 2x + 1
x^2 + 2x - 8 = 0
(x + 4)(x - 2) = 0
Can you take it from here?
