4x²+2x-9y²+3y,x²+6y-y²-9,x²-xy-2y&#

4x²+2x-9y²+3y=(4x²-9y²)+(2x+3y)=(2x+3y)(2x-3y)+(2x+3y)=(2x+3y)(2x-3y+1)x²+6y-y²-9=x²-(y-3)²=(x+y-3)(x-y+3)x²-xy-2y²-x-y,=(x+y)(x-2y)-(x+y)=(x+y)(x-2y-1)x²-y²-x-y=(x+y)(x-y)-(x+y)=(x+y)(x-y-1)2m(a-c)-5(c-a) =2m(a-c)+5(a-c) =(a-c)(2m+5)3a(x-y)²-2(y-x)²=3a(x-y)²-2(x-y)²=(3a-2)(x-y)²