(2/5X-3/5Y)(5/2X-5/3Y)=?
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
若3x-5y=0,则x+y/x=(),x-y/y=(),2x-3y/2x+3y=( )
2(x-y)+3(x+y)2-5(x-y)-8(x+y)2-(x-y)
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
10/x+y+3/x-y=-5 15/x+y-2/x-y=-1(用换元法解此方程组)
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
数学(x-y)^5*(y-x)^3*(x-y)^2
计算:(3x-y)2-(2x+y)2+5x(y-x)
(3x-y)²-2x(4x-5y)-(x+2y)²
3(x+y)-4(x-y)=11 2(x-y)+5(x+y)=27 解这个两元一次方程组
已知x-5y=0,求分式x²-2xy+y²/3x+y × (y-x)的值