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 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y 2(x+y)-3(x-y)=1 6(x+y)+7(x-y)=51 解方程组 2(x+y)-3(x-y) =1 6(x+y)+7(x-y)=51大神们帮帮忙 解方程组﹛2(x+y)-3(x-y)=1 6(x+y)+7(x-y)=51 (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 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 ｛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