Question

Factorise the following expression by splitting the middle term
a²-a-72​

Answer 1

Answer:

see the attached document for the steps

Answer 2

$= {a}^{2} - a - 72 \\ \\ = {a }^{2} - (9a - 8a) - 72 \\ \\ = {a}^{2} - 9a + 8a - 72 \\ \\ = a(a - 9) + 8(a - 9) \\ \\ = (a - 9)(a - 8)$

Hope it helps