{3（x-y-1）=6-2y x/2+y/3=1}

（x+y）/2- x-y/2=6 3(x+y)=4(x-y) 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 已知：2x+y=6,x-3y=1 求7y(x-3y)(x-3y)-2(3y-x)(3y-x) 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= (x+y)(x-y)+(x-y)^2-(6x^2×y÷2y-2xy^2÷2y)其中x=-3,y=1/3 把下列各式分解因式 x(x+y)(x-y)-x(y+x)² 2 已知2x+y=6,x-3y=1,求7y（x-3y）²把下列各式分解因式x(x+y)(x-y)-x(y+x)²7、已知2x+y=6,x-3y=1,求7y（x-3y）²-2（3y-x）³的值 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 已知2x-y=0,求分式【1+（3*y*y*y/x*x*x-y*y*y）】/【1+（2y/x-y）】的值注：x*x*x-y*y*y=（x-y）*（x*x+xy+y*y） 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 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 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（） 3x+y=2 -y/x+y=123x+y=2 （-y/x）+y=12 x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 （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