(x-3y)(x-1/2y)
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
1) (x+y)^2-(x+y)^3 2) (x-y)^2-(x-y)^3 3)(x-y)^2-(y-x)^3 因式分解
先化简再求值:(x-2y)²-(x+2y)(x-2y)-(x-3y)(x-y).其中x²+9y
(x-y)(x-2y)-(3x-2y)(x-3y)
1.((y+2x)(-2x+y)+4(x+2y)^2)/3y 2.(2(x-y)^3-8(x-y)^2(x+y)+6y(
化简:(x+y)+(2x+y/1*2)+(3x+y/2*3)+...+(9x+y/8*9)
10/x+y+3/x-y=-5 15/x+y-2/x-y=-1(用换元法解此方程组)
已知x=3分之1,y=二分之一,求代数式x-(x+y)+(x+2y)-(x+3y)+...-(x+13y)的值
2(x-y)+3(x+y)2-5(x-y)-8(x+y)2-(x-y)
(X-3Y)(X+3Y)-(X+2Y)(X-4Y)-(2X-Y)2的平方
(1)(2x-y)(2x+y)-(x-3y)^2
1、当(x+y)/(x-2y)=3时,2x/y=?