We need to solve the given equation,
First step is to multiply by the common denominator of 2 and 3 which is 6 to each sides of the equation to get rid of the fraction form. So,

2a= 3(a-1) (By simplifying)
2a=3a-3 (By distributing property).
2a-3a=-3 (Subtracting 3a from each sides).
-a = -3
a=3
So, the solution is a=3.