4x²-y²+2y-1化简

化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 化简：[(2x-y)平方+（2x+y)(2x-y)-4x(x-y+1)]÷2x 化简：（2x-y)²-4(x-y)(x+y) 1) (2x+5y)(2x-5y)(-4x^2-25y^2) 2) [（x+y)(x-y)-(x-y)^2+2y(x-y 1 4(x-y+1)+y(y-2x) 把4（x-y+1)+y(y-2x)因式分解 4(x-y+1)+y(y-2x) 化简：(x+y)(x-y)-2(4-y^2+1/2x^2) 赶紧回答吧, 化简,并求值2(x-2y)²-4（x+3y)(x-3y)-2(x-y).(y+x)-5(-x-1)² 化简：{(x+2y)(2y-x)-4y(-x+y) } / (-2x) （x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3) {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1