#### Answer

a=4

#### Work Step by Step

Start with the given equation: 5a-15+9a=3a+29
Then combine like terms by subtracting 3a to the left and adding 15 to the right.
The resulting equation is 5a+9a-3a=29+15
Combine like terms to get 11a=44
Lastly, divide by 11 on both sides to get a=4.