y-x/7-x+y/6=1/2 5(x+y)-2(y-x)=1
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
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
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
1、x(x-y)(x+y)-x(x+y)^2
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
若2x-3y+4=0则x(x*x-1)+x(5-x*x)-6y+7
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
分式的加减:[(x/y-y/x)除以(x+y)+x(1/y-1/x)]除以1+x/y,其中x=5,y=2
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值
x+y/2+x-y/3=5/6;x=y/6-x-y/3=1/2
7x-3y/5=5x-y/3-x+y/2 x-1/5=y+1/3