x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20

{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 （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 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 【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 解二元一次方程组：3(x+y)-4(x-y)=4,x+y/2+x-y/6+1x+y/2+x-y/6+1=1 x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 81/8*(-x-y)^6*(x-y)^3*4/9(x+y)^4*(y-x)^2 2（x+y)-3(x-y)=3 ,4(x+y)+3(x-y)=15 4x-3y/x-2y÷6y-8x/y-2x 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 2(x+y)-3(x-y)=1 6(x+y)+(x-y)=51 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2