根据3(x+y)-2(x-y)=11,4(x+y)+3(x-y)=9可得出x+y= ,x-y=
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
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)
{4/(x+y)+6/(x-y)=3 {9/(x-y)-1/(x+y)=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)=4 {x+y/2 + x-y/6=1
(x+y)(x+2y)(x+3y)(x+4y)=-40
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
9y=3x-(x-1),4(x+y)-(2x+4)=8y
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