nomor 3 dan 6 aja ya pakai caranya

3. a²-1 = (a+1)(a-1)
[tex] \frac{3}{(a + 1)(a - 1)} - \frac{2(a - 1)}{(a + 1)(a - 1)} [/tex]
[tex] \frac{ 5 - 2a}{(a + 1)(a - 1)} [/tex]
6. a²+3a-4 = (a+4)(a-1)

2a -1(a+4)
---------------
(a+4)(a-1)

[tex] \frac{a - 4}{(a + 4)(a - 1)} [/tex]