数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y
数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y
[(x+2y)²-(x+y)(3x-y)-5y²]÷(2x),其中x,y满足x²+4x+y
2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
化简,并求值2(x-2y)²-4(x+3y)(x-3y)-2(x-y).(y+x)-5(-x-1)²
|3x-y+5|+(2x-y+3)²=0 求x=?y=?
已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y
数学(x-y)^5*(y-x)^3*(x-y)^2
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
化简(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90)
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1