x+y=20-6 3x+y=30x、y是多少

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=30x、y是多少 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x {6/x+y+10/x-y=30 6/x+y-10/x-y=-1 2(x+y)-3(x-y)=1 6(x+y)+(x-y)=51 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 （x+y）/2- x-y/2=6 3(x+y)=4(x-y) x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 6(x+y)的平方-11(x+y)(x-y)+3(x-y)的平方=? 化简 x / y(x+y) - y / x(x+y) =