Question

25 (a+b)^2 - 16 (a-b)^2
Find answer by using factorisation

Answer 1

{5(a+b)}²-{4(a-b)}²

{5(a+b)-4(a-b)}{{5(a+b)+4(a-b)}

{5a+5b-4a+4b} {5a+5b+4a-4b}

{a+9b} {9a+b}

Answer 2

25(a+b)^2 - 16(a-b)^2

=> [ 5(a+b)]^2 - [ 4(a-b)]^2

=> (5a +5b)^2 - (4a-4b)^2

=> (5a +5b - 4a +4b) ( 5a +5b +4a - 4b)

=> (a +9b) (9a+b)