x+y=20-6 3x+y=30
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
x+y=20-6 3x+y=30
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
{4/(x+y)+6/(x-y)=3 {9/(x-y)-1/(x+y)=1
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
|x|+|y|=30 2|x|-3|y|=20 求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)