2x²/3y²×5y/6x÷10y/21x^2
计算:(x+2y)(3x-5y)-(6x的四次方y²-2x²y²)÷(2x²y&
急![(3x+y)²-3(3x-y)(x+y)-(x-3y)(x+3y)]÷(2xy)
合并同类项:-6x²y-x+5x²y-2x+x³y+3x
(2x²/3y²)*(5y/6x)/(10y、21x²)
{(x+2y)(x-2y)+[2(x-y)]²}÷6x=?
(3x-y)²-2x(4x-5y)-(x+2y)²
先化简,在求值:(x-y)²+(3x-2y)(2x+y)-x(6x-y)
计算:(x-y)^7÷(y-x)^6+(-x-y)^3÷(x+y)^2
[(x+2y)^2 -(x+y)(3x-y)-5y^2]÷2x
化简(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90)
2(2x+3y)(3x+2y)-(6x-y)(2x-5y)
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5