(-2y/3x)^-2÷5y/6x÷(-3x^2/y)^3
计算:(x-y)^7÷(y-x)^6+(-x-y)^3÷(x+y)^2
[(x+2y)^2 -(x+y)(3x-y)-5y^2]÷2x
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y
[(x+2y)²-(x+y)(3x-y)-5y²]÷(2x),其中x,y满足x²+4x+y
数学(x-y)^5*(y-x)^3*(x-y)^2
[(2x+y)(x-3y)+y(x+3y)]÷(2x)计算,
2(2x+3y)(3x+2y)-(6x-y)(2x-5y)
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
已知xy=-2,x-y=3,求(x+y)(x-y)-y^2+(x-y)^2-(6x^2y-2xy^2)÷2y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
x^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8