4y+6x=6 6y+2x=4.6

{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 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= ｛4/(x+y)+6/(x-y)=3 ｛9/(x-y)-1/(x+y)=1 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 已知x.x+y.y+8x+6y+25=0,求代数式(x.x-4y.y)/(x.x+4xy+4y.y)-x/(x+2y)的 4x-2y-6y*-y-3x+5y* *=2 就是平方 4x-(2x+y+16)/2=-6y 2x+3y=7-x-2y 3分之2(X-Y)-4分之X+Y=-1,6(X+Y)-4(2X-Y)=16