You can break the equation into two groups:
6a² + 5a - 6
(9a - 6) + (6a² - 4a)
Simplify:
(9a - 6)
3(9a - 6)
(3a - 2)
--------------------------
(6a² - 4a)
2a(6a² - 4a)
(3a - 2)
--------------------------
(3a - 2)(2a+3)
You can't simplify any further, so that will be your answer.
Answer:
(2a + 3)(3a - 2)
