Question

(√х-√у)в квадрате+(√х+√у)в квадрате=?

Answer 1

(√х-√у)²+(√х+√у)²=(√х)²-2√х√у+(√У)²+(√х)²+2√х√у+(√У)²=х-2√х√у+у+х+2√х√у+у=2х+2у

Answer 2

$(sqrt{x}-sqrt{y})^{2}+(sqrt{x}+sqrt{y})^{2}=((sqrt{x})^{2}-2sqrt{x}cdotsqrt{y}+(-sqrt{y})^{2})+ ((sqrt{x})^{2}+2sqrt{x}cdotsqrt{y}+(sqrt{y})^{2})=(x-2sqrt{xy}+y)+ (x+2sqrt{xy}+y)=x-2sqrt{xy}+y+x+2sqrt{xy}+y=(x+x)+(2sqrt{xy}-2sqrt{xy})+(y+y)=2x+2y$