(1/x²+x) +(1/x²+3x+2) +(1/x²+5x+6)+(1/x²
(x+1-1/1-x)÷(x-x²/x-1) (x-4/x-x-6+ x+2/x-3)÷x+1/x-3
6x+(2x²-3x)-(x²-1)
x²+3x+9/(x²-27)+6x/(9x-x²)-(x-1)/(6+2x)
x(x²-1)+2x²(x+1)-3x(2x-5)计算
((x²-5x+6)/(12-7x+x²))²÷((x²+3x+2)/(x
代数式6x+2x²-3x+x²+1,其中x=-5
(2x²-2x+3)(-x³+x-1)
5x²+[x²+(5x²-2x)]-2(x²-3x),其中x=-1
(x+1)/(x²+3x+2)+(x²-2x)/(x²-4)
x除x²+3x+2,-x除x²+2x+1与-1除3x+6
计算:[(-5+x)(-x-5)]² (x+3)²-(x+2)(x-1) (3x-a)(3x+a)(
根号x²-2x+1(x