Answer:
None.
Step-by-step explanation:
5/a - 2 / (1 - a) = 2 (a - 1)
Multiply each term by a(1 - a)(a - 1):
5 (1 - a)(a - 1) - 2a(a - 1) = 2a(1 - a)
5( a - 1 - a^2 + a) - 2a^2 + 2a = 2a - 2a^2
5(-a^2 + 2a - 1) - 2a^2 + 2a = 2a - 2a^2
-5a^2 + 10a - 5 - 2a^2 + 2a - 2a + 2a^2 = 0
-5a^2 + 10a - 5 = 0
-5(a^2 - 2a + 1) = 0
= -5(a - 1)^2 = 0
So a = 1.
But a = 1 cannot be a root because 2/ 1 - a would be 2/0 which is undefined.
Also 2 / (a - 1) is undefined.