x+y/2+x-y/3=6 4（x+y）-3（x-y）=-20,哥哥姐姐们帮帮忙吧--谢谢了现在,就现在

（x+y）/2- x-y/2=6 3(x+y)=4(x-y) {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 （y-x）^4（x-y）^3+2（x-y）^6（y-x） 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/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)= 如果A={（x,y）|x,y+2>0},B={（x,y）|2x+3y-6>0},C={（x,y）|x-4 1.（（y+2x)(-2x+y)+4(x+2y)^2)/3y 2.（2(x-y)^3-8(x-y）^2(x+y)+6y(x-y)^2）/2（x-y)^2 【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 计算：（3x-4y）-[-（2y+x）+（x-3y）]-6x 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 已知（x+y）2 =2,(x-y)3 =3,求(x+y)7(x-y)2(x+y)3(y-x)4 的值 若x+y=4,则多项式1/2(x+y)+4(x-y)-3（x-y）-3/2(x+y)-x+y值是（） y'=（y/x）^2+y/x+4微分方程 x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2