3x-2(2y+1)=4x+2y+12=4(x-1).
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
9y=3x-(x-1),4(x+y)-(2x+4)=8y
已知4x=9y求(1)x+y/y (2)y-x/2x
若x=-1/4,能否确定代数式(2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)的值?
分解因式计算:x^2(x-y)+(y-x)=?x^3+x^2+1\4x=?(2x+y)^2-(x-2y)^2=?
[(2x+y)^2+(y+2x)(y-2x)-2y(4x-y)]/4y,其中x=1/2,y=1/3
先化简,再求值:[(x+y)(x-y)-(x-y)^2+2y(x-3y)]/(-4y),其中x=1,y=-2
若2x-3y+4=0则x(x*x-1)+x(5-x*x)-6y+7
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
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