Question

Разложение на множители
(a-b-c) ²- (a+b-c) ²

Answer 1

$\displaystyle\bf\\(a-b-c)^{2} -(a+b-c)^{2} =(a-b-c-a-b+c)(a-b-c+a+b-c)=\\\\=-2b(2a-2c)=-2b\cdot 2(a-c)=-4b(a-c)$