计算.(1)(x-1)(x2+x+1);(2)-5x(-x2+2x+1)-(2x+3)(5-x2);(3)(3x-y)(
(-2x2+3x)-[5x-(2x2+1)-x2].
分式计算:2x/x2-x-2÷(1-x/x+1)-x2+2x/x2-4
计算.(1)(x-1)(x2+x+1);(2)-5x(-x2+2x+1)-(2x+3)(5-x2);(3)(3x-y)(
计算[x(3-4x)+2x2(x-1)]÷(-2x)
计算:(1)x2+9xx2+3x+x2−9x2+6x+9
x(x-1)-(x2-y)=-3,求x2+y2-2xy的值
5x2-(x-2)(3x+1)-2(x+1)(x-5)
(x2+5x+4)2+2(x2+5x+4)2+1=(x2+.
证明:(x3+5x2+4x-1)-(-x2-3x+2x3-3)+(8-7x-6x2+x3)的值与x无关.
(x-6)(x2+x+1)-x(2x+1)(3x-1)
解方程 x(x-6)+2x(x-3)=3(x2-x-1) 解不等式:2x2(x-3)+4(x2-x)≥x(2x2-2x+
3x2-[7x-(4x-3)-2x2]