5x-5y=-12 -3y+10y=16

5x-5y=-12 -3y+10y=16 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai 先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y 5(x+y-2)=3-y （5x+3y)(3y-5x)-(4x-y)(4y+x)= 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy) [-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y- |x|=3 |y|=5 |x-y|=|x|+|y| 求 X+Y和 X-Y 等于多少 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1