Question

Factorise (a+b)2-c2.and 4x2-81y2

Answer 1

Hey,

Your answer is here,

(1)
${(a + b)}^{2} - {c}^{2} \\ {(a + b)}^{2} - {(c)}^{2} \\ (a + b + c)(a + b - c)$
(2)
$4 {x}^{2} - 81 {y}^{2} \\ {(2x)}^{2} - {(9y)}^{2} \\ (2x + 9y)(2x - 9y)$

By applying formula:-
${a}^{2} - {b}^{2} \\ (a + b)(a - b)$
Hope it helps