The answer is true here's the reasons: (3 x 5) x 9 is what i started to solve first.
The first thing i did was i took the 3 and multiply it by 5 which gave me 15 then multiply it by 9 it gave me 135. So that was the first side done
The second part on 3x (5 x 9) I took the 5 and multiply it by the 9 which is 45 and then multiply it by 3 which gave me the same answer as the other side. Which would look like this 135=135
So your answer should be true hope this helps. :)