Question

Simplify : (√ + √ ) (√ − √) ( + )( 2 + 2 )

Answer 1

$(\sqrt{x}+\sqrt{y})(\sqrt{x}-\sqrt{y})(x+y)(x^2+y^2)\\\\=[(\sqrt{x})^2-(\sqrt{y})^2](x+y)(x^2+y^2)\\\\=(x-y)(x+y)(x^2+y^2)\\\\=(x^2-y^2)(x^2+y^2)\\\\=(x^2)^2-(y^2)^2\\\\=x^4-y^4$

$Used:\\\\(\sqrt{a})^2=a\\\\(a-b)(a+b)=a^2-b^2\\\\(a^n)^m=a^{nm}$