解方程3(2X-Y)+4(X-2Y)=87 2(3X-Y)-3(X-Y)+82
解方程x+y+(x+y/2)=15 3x+5y+4(x+y/2)=62
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)
x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20
{(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20
4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
(x+y)(x+2y)(x+3y)(x+4y)=-40
(x+3y-4)(2x-y)
x/x-y*y^2/x+y-x^3y2/x^4-y^4/x^2/x^2+y^2
[(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y)