明天中午要你们赶紧的哈.嘿嘿.a-1/a+1-a^2-1/a^2+a(有关于通分的）2.（a-1/2-a+1/1）·（a^2-1)代数a=根号3-33.（x-1/1-x+1/1）÷2x^2-2/x（化简）哪位大神快点吧没

Question

明天中午要 你们赶紧的哈. 嘿嘿.

  a-1/a+1-a^2-1/a^2+a   ( 有关于通分的）     2.  （a-1/2-a+1/1）·（a^2-1)   代数  a=根号3-3                  3.（x-1/1-x+1/1）÷2x^2-2/x        （化简）   

哪位大神快点吧 没时间了 求 前面是分母 后面是分子

Answer 1

解1题
原式=(a-1)/(a+1) -(a²-1)/(a²+a)
=(a-1)(a+1)/(a+1)² -(a-1)(a+1)/(a²+a)
=(a-1)(a+1)/[(a+1)²-(a²+a)]
=(a-1)(a+1)/(a²+2a+1-a²-a)
=(a-1)(a+1)/(a+1)
=(a-1)/1
解2题
原式=[ (a-1)/2 -(a+1)/1 ]·(a²-1)
=[ (a-1)/2 -(a+1)/1 ]·(a-1)(a+1)
=(a-1)/2 ·(a-1)(a+1) -(a+1)/1 ·(a-1)(a+1)
=2(a+1) -(a-1)
=2a+2-a+1
=a+3
当a=根号3 -3时
原式=根号3 -3+3=根号3
解3题
原式=[ (x-1)/1 -(x+1)/1 ]÷(2x²-2)/x
=[ (x-1)/1 -(x+1)/1 ]×x/[2(x-1)(x+1)]
=(x-1)/1 ·x/[2(x-1)(x+1)] -(x+1)/1 ·x/[2(x-1)(x+1)]
=x/[2(x+1)] -x/[2(x-1)]
=x/[2(x+1)-2(x-1)]
=x/(2x+2-2x+2)
=x/4