y=2x+1 -2x+3y=-9 求算X和Y
已知4x=9y求(1)x+y/y (2)y-x/2x
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
3x=2y+1;x=9y;求x,y的值?
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
3x+2y=5 3y+2x=5 求x和y
已知2x-y/x+2y=3,求2(2x-y)/x+2y-9(x+2y)/2x-y+3的值.
1奥数题x-2y/x+2y=3,求x-2y/3(x+2y)-3(x-2y)/x-2y的差
已知方程组2X+Y=6和X-3Y=1不解方程组,求7Y(X-3Y)^2-(3Y-X)^3
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
x+y=1,xy=-1/2,求x(x+y)(x-y)-x(x+y)2