x²+2x-1 =x²+2x+1-2=(x+1)²-(√2)² =(x+1+√2)(x+1-√2)2x²+xy-y²-4x+5y-6=(2x-y)(x+y)-4x+5y-6=(2x-y)(x+y)+(2x+2y)-6x+3y-6=(2x-y)(x+y)+2(x+y)-6x+3y-6=(x+y)(2x-y+2)-3(2x-y+2)=(...