Question

Factorise it (a-5)^2-36

Answer 1

i hope this Will help you

Answer 2

$36 \: is \: the \: square \: of \: 6 \\ \\ - > (a - 5) {}^{2} - (6) {}^{2} \\ \\ now \: it \:is \: in \: the \: form \: (a + b)(a - b) = a {}^{2} - b {}^{2} \\ \\ so \: (a - 5) {}^{2} - (6) {}^{2} \\ \\ = (a - 5 + 6)(a - 5 - 6) \\ \\ = (a + 1)(a - 11)$