Question

(vii) (l + m)
- 41m
m)
(Hint: Expand (l+m) first)​

Answer 1

Answer:

i) (l + m)2 − 4lm

= l2 + 2lm + m2 − 4lm

= l2 − 2lm + m2

= (l − m)2 [(a − b)2 = a2 − 2ab + b2]

(ii) a4 + 2a2b2 + b4

= (a2)2 + 2 (a2) (b2) + (b2)2

= (a2 + b2)2 [(a + b)2 = a2 + 2ab + b2]