(√x-√y)^2+(√x+√y)^2
(2√a+3√b)^2+(2√a+3√b)(2√a-3√b)
(√c-7√b)(c+7√cd+49d)-(√c+7√d)(c-7√cd+49d)
(√m-√n)^2-(√m-√t)^2-(√n-√t)^2

(√x-√y)²+(√x+√y)²=х-2√х√у+у+х+2√х√у+у=2х+2у(2√a+3√b)²+(2√a+3√b)(2√a-3√b)=4а-12√а√в+9в+4а-9в=8а-12√(ав)(√c-7√d)(c+7√cd+49d)-(√c+7√d)(c-7√cd+49d)=(√с)³-(7√d)³-(√с)³-(7√d)³=-343d√d-343d√d=-686d√d(√m-√n)²-(√m-√t)²-(√n-√t)²=m-2√m√n+n-m+2√m√t-t-n+2√n√t-t=-2√m√n+2√m√t+2√n√t-2t