3(x+y)-4(x-y）=4 x+2y+3z=5x+y/2+x-y/6=1 2x+3y+6z=95x+3y+9z=15 3(x+y)-4(x-y）=4 x+2y+3z=5 两式一道！（二元一次方程组）x+y/2+x-y/6=1 2x+3y+6z=9 5x+3y+9z=15 （三元一次方程组）

（x+y）/2- x-y/2=6 3(x+y)=4(x-y) (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 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（） 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 y'=（y/x）^2+y/x+4微分方程 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 2（x+y)-3(x-y)=3 ,4(x+y)+3(x-y)=15 （y-x）^4（x-y）^3+2（x-y）^6（y-x） （x-y）^3×（y-x）^4+（x-y）^2×（y-x）^5 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 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 12（x+y）^3（y-x）/【4（x+y）^2(x-y)】 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27