-5x(y-x)-(y-x)^2= (y-x)(-5x-y+x)= (y-x)(-4x-y)= -(y-x)(4x+y)= (x-y)(4x+y)
Или
5x(x-y)-2(y-x)^2= 5x^2-5xy-2y^2+4xy-2x^2= 3x^2-xy-2y^2
-5x(y-x)-(y-x)^2= (y-x)(-5x-y+x)= (y-x)(-4x-y)= -(y-x)(4x+y)= (x-y)(4x+y)
Или
5x(x-y)-2(y-x)^2= 5x^2-5xy-2y^2+4xy-2x^2= 3x^2-xy-2y^2