For this case the correct expression is:
15 / (a ^ 2 - 1) = 5 / (2a - 2)
Rewriting we have:
3 / (a ^ 2 - 1) = 1/2 (a - 1)
6 / (a ^ 2 - 1) = 1 / (a - 1)
6 (a - 1) = (a ^ 2 - 1)
6 (a - 1) = (a-1) (a + 1)
(a + 1) = 6
a = 6-1
a = 5
Answer:
The solution is:
a = 5
