1.1/a(a+1) + 1/（a+1)(a+2) + 1/（a+2)(a+3) + .+1/（a+2003)(a+20

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/11/08 14:46:58

1.1/a(a+1) + 1/（a+1)(a+2) + 1/（a+2)(a+3) + .+1/（a+2003)(a+2004)
2.1/x - 1/x-1 （x²-1/x -x+1）
3.1/a+2 + a-2
2.(1/x)- (1/x-1)【（x²-1/x）-x+1】用小括号括的是一个分式前面是分子后面是分母
3.（1/a+2）+a-2

1. 1/a(a+1) + 1/（a+1)(a+2) + 1/（a+2)(a+3) + .+1/（a+2003)(a+2004)
=1a-1/(a+1) + 1/(a+1)-1/(a+2) +1/(a+2)+.-1/(a+2003)+1/(a+2003)-1/a+2004)
=1/a-1/(a+2004)
=(a+2004-a)/{a(a+2004)
=2004/{a(a+2004)
2. 1/x - 1/x-1 （x²-1/x -x+1）
= 1/x - 1/(x-1) {(x^2-1) -x(x-1)}/x
= 1/x - 1/(x-1) {(x^2-1 -x^2 +x)}/x
= 1/x - 1/(x-1)*(x-1)/x
= 1/x - 1/x
=0
3. 1/(a+2) + ( a-2)
={1+(a+2)(a-2)}/(a+2)
={1+a^2-4)}/(a+2)
=(a^2-3)/(a+2)

(a 1)(a 2)(a 3)(a a(a-1)(a-2)(a-3)(a-4)因式分解【1】a+a=a×a a= [ ]【2】a×a=a÷a a=[ ]【3】a×a=a－a a=[ ] [4]a－a=a＋a a/a-1÷（a-a/2a-1) (a+1)(a+2)(a-3)计算 1A,2A,3A... 因式分解(a^2-a-1)(a^2-a-2)-20 1+a^1+a^2+a^3+.+a^n=? 计算a^3/a-1-a^2-a-1 已知 a>1,求证a^3>a+1/a-2 因式分解：a(a-2)(a-3)(a+1)+2 (a-1)(a-2)(a-3)(a-4)-3因式分解,