Simplifying fractions - which answer is correct?

Question

Hello, I'm trying to figure out which is the correct answer to the following exercise :

https://gyazo.com/5df2e13d2ecbaf80cca2550f617746d4

The answer give as the correct one is : 

https://gyazo.com/4a0124747df202e45cd0a26e5f63b343

However, in an older edition of the book, a different answer is given : 

https://gyazo.com/4da312f12946bd2005b1a5c948202927

Answer 1

5b(a-3) a+b

------- * ----------

4(a-3) 6b^2

5(a+b)

------- <--- (a-3) cancels; factor of B cancels

24b