3x-1/2x²-x+1
(x+1-1/1-x)÷(x-x²/x-1) (x-4/x-x-6+ x+2/x-3)÷x+1/x-3
x-1)(X-2)(x-3)...(x-50)+x(x-2)(X-3)...(X-50)+...+x(x-1)(x-2)
6x+(2x²-3x)-(x²-1)
(2x²-2x+3)(-x³+x-1)
x²+3x+9/(x²-27)+6x/(9x-x²)-(x-1)/(6+2x)
x+2/x+1-x+3/x+2-x+4/x+3+x+5/x+4
x^5+x^4 = (x^3-x)(x^2+x+1)+x^2+x
(x+1)/(x²+3x+2)+(x²-2x)/(x²-4)
x(x²-1)+2x²(x+1)-3x(2x-5)计算
①2(x+3)(x-3)=x²+(x-1)(x+1)+2x
(x-1)(2x²-3x+2)-x(x+1)(x-2)
1+x+x^2+x^3+.+x^99+x^100