Question

Factorise:

$\text{(a)}{a}^2+14a+48$

$\text{(b)}{m}^2–10m–56$

Answer 1

$\text{(a)}{a}^2+14a+48$

$=a^2+6a+8a+48$

$[6+8=14;6\times 8=48]$

$=a(a+6)+8(a+6)$

$=(a+6)(a+8)$

$\text{(b)}{m}^2–10m–56$

$=m^2–14m+4m–56$

$[14–4=10;4\times 4=56]$

$=m(m–14)+4(m–14)$

$=(m–14)(m+4)$