5x-y=51,x-y=3,则x= ,y=
已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy)
已知x-y/x+y=3,求代数式5(x-y)/x+y-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
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
(5x+3y)(3y-5x)-(4x-y)(4y+x)=
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
若3x-5y=0,则x+y/x=(),x-y/y=(),2x-3y/2x+3y=( )
x+y=5; x^y+y^x=17
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
|x|=3 |y|=5 |x-y|=|x|+|y| 求 X+Y和 X-Y 等于多少
已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?