Question

The value of (x + y)2+ (x - y)2is?


answer is 2(x^2+ y^2) kindly guide me step by step

Answer 1

$({x + y})^{2}$
can be written as
${x}^{2} + {y}^{2} + 2xy$
${(x - y})^{2} = x^{2} + {y}^{2} - 2xy$
adding them we get 2(x^2+y^2). as +2xy -2xy get cancelled...