（4x-2y)-(-(-2y-x)+(x-y))-5x 化简

化简：（2x-y)²-4(x-y)(x+y) 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 1) (2x+5y)(2x-5y)(-4x^2-25y^2) 2) [（x+y)(x-y)-(x-y)^2+2y(x-y 化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方 x^2-y^2/x+y-4x(x-y)+y^2/2x-y, 化简2（2X-7Y)(7Y+2X)+X^2-(-4X+5Y)(-5Y-4X) 1、x(x-y)(x+y)-x(x+y)^2 化简(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90) 化简：[(x+2y)^2-(x+y)(3x-y)-5y^2]/2x 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)=11,2(x-y)+5(x+y)=27