(x-2)×180°÷x+(y-2)×180°÷y+(z-2)×180°÷z=360° 化简是多少?

[(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x² 化简3x-2/(x+y)[(x+y)/3x-x-y]÷(x-y)/x 1／2x－（x+y／2x -x-y）÷（x+y) 化简：[(2x-y)平方+（2x+y)(2x-y)-4x(x-y+1)]÷2x 先化简,再求值:y(x-y)-x(x+y)/x²-y²÷x²+y²/x+y,其中x=2,y=-1 1-[(x-y)/(x+2y)]÷[(x+y)(x-y)/(x+2y)²] 1-[(x-y)/(x+2y)]÷[(x+y)(x-y)/(x+2y)²]= (x-y/1-x+y/1)÷2y/y-x计算错了，是(1/x-y-1/x+y)÷2y/y-x [(-2x-y)^2-(2x+y)(2x-y)]÷2y-1/2y 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 【(1)/(x-y)+(1)/(x+y)】÷(2x)/(x²-2xy+y²) [(x-y)^2+(x+y)(x-y)]÷2x,其中x=2011y=-1 [(x-y)^2+(x+y)(x-y)]÷2x,其中x=2011y=1 [(x+y)(x-y)-(x-y)²+2y(x-y)]÷4y 先化简,再求值 （1）[(x-y)的平方+（x+y)(x-y)]÷2x 其中X=2010,y=2009 （2)y(x+y)+(x+y)(x-y)-x的平方,先化简，再求值（1）[(x-y)的平方+（x+y)(x-y)]÷2x 其中X=2010,y=2009（2)y(x+y)+(x+y)(x-y)-x的平方,其中x=-2,y=二分 (x²-4y²)÷(2x+y)/xy×1/x(2y-x）(2x+y)/xy 1/x(2y-x） 都是一项 计算x²-x/x²×x/1-x和x²-4y²/x²+2xy+y²÷x+2y/x²+xy 1.(x^3-x^2-4x+1)/(x^2-3x+2)-(x^3-2x^2-9x+21)/（x^2-5x+6）+（x^2-3x+8）/（x^2-4x+3）2.{(x^2)/（x-y)}*{y/(x+y)}-{(x^4y)/(x^4-y^4)}÷{（x^2/x^2+y^2）^2}