Question

разложите не множители:
x - y - 2x² + 2y²

Answer 1

$x-y-2 x^{2} +2 y^{2} =2( y^{2} - x^{2} )+( x-y)= \ 2(y- x)(y+ x)-(y- x)= (2y+2 x-1)(y- x)$