Question

Factorise the following expressions:-
$a^2-a(b+3)+3b$

Answer 1

$a^2-a(b+3)+3b$

$\Rightarrow a^2-ab-3a+3b$

$\Rightarrow a(a-b)-3(a-b)$

$\Rightarrow (a-b)[a-3]$

$\Rightarrow (a-b)(a-3)$