Question

plz anwer me . factorise it​

Answer 1

SIMPLIFICATION

$2 {(x - 2y)}^{2} - {50y}^{2} \\ \\ \\ \\ \implies 2( {x}^{2} - 4xy + 4 {y}^{2} ) - 50 {y}^{2} \\ \\ \\ \\ \implies 2 {x}^{2} - 8xy + 8 {y}^{2} - 50 {y}^{2} \\ \\ \\ \\ \implies \boxed{{2x}^{2} - 8xy - 42 {y}^{2} } \: \:$

Then we will factorise this expression ;

2x^2 - 8xy - 42y^2

=> 2( x^2 - 4xy - 21y^2)

IMPORTANT IDENTITIES :-

(a + b)^2 = a^2 + b^2 + 2ab

(a - b)^2 = a^2 + b^2 - 2ab

(a + b)(a - b) = a^2 - b^2