Question

Factorise

(l + m)2 – 4lm​

Answer 1

Step-by-step explanation:

$(i) (l + m)2 − 4lm$

$= l2 + 2lm + m2 − 4lm$

$= l2 − 2lm + m2 = (l − m)2$

$[(a − b)2 = a2 − 2ab + b2]$