解2x+y=4x-y-1/2=10+6x+2y/4

{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 解方程组：2(x-y)/3-x+y/4=-1 ,6(x+y)-4(2x-y)=16 解二元一次方程组{3(x+y)-4(x-y)=4,x+y/2+x-y/6=1 解方程组3(x+y)-4(x-y)=4和(x+y)/2+(x-y)/6=1 要求 解方程组：｛(X-1)(Y+1)=(X+1)(Y+1)｛X(2+Y)-6=Y(X-4) 解方程组 10（x-y)=3(x+y)+15 6(x+y)=4(2x-y)+16 解二元一次方程组：3(x+y)-4(x-y)=4,x+y/2+x-y/6+1 解二元一次方程组{3(x+y)-(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 已知4x=9y求(1)x+y/y (2)y-x/2x