2x-y/x+y=4,则4x-2y/2x+2y+3x+3y/2x-y
(x+3y-4)(2x-y)
x/x-y*y^2/x+y-x^3y2/x^4-y^4/x^2/x^2+y^2
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
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)=11,2(x-y)+5(x+y)=27
(x+y)(x+2y)(x+3y)(x+4y)=-40
(2x+y)(2x-3y)+x(2y+y) 2a(x-y)-4b(x-y)
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^2-y^2/x+y-4x(x-y)+y^2/2x-y,