Question

Factorize:
9(x-2y)^2 -4(x-2y)-13

Answer 1

$take \: x - 2y = a \\now \: eq. \: is \\ 9 {a}^{2} - 4a - 13 \\ = 9 {a}^{2} - 13a + 9a - 13 \\ = a(9a - 13) + 1(9a - 13) \\ = (9a - 13)(a + 1) \\ = (9(x - 2y) - 13)(x - 2y + 1) \\ = (9x - 18y - 13)(x - 2y + 1)$