{3（x-y-1）=6-2y x/2+y/3=1}

{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 已知：3x=8y.求（1）x+y/y (2)2x+3y/x-2y 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 (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 2(x+y) 3x+3y=24 x+y/2x x y/2y= 1 (1)已知x+y=6,x²-y²=5,求x-y的值（2）若x+y=3,x²+y² 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 x+y)(x-y)+(x-y)^2-(6x^2y-2xy^2)/2y,其中x=-2,y=1/3 若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 因式分解 (1)6(x-y)^3-3y(y-x)^2 (2)x(x-y)(a-b)-y(y-x)( x+y=3 x+2y=9 3/x+1=y y-x=3 y=2x-3 y-3x=1 2(x+1)-y=6 7x-5y=-9