Here is how I would show the work for this problem
5- (a-4) = 3 (a+2)
5-a+4 = 3*a+3*2
5-a+4 = 3a+6
-a+9 = 3a+6
-a+9+a = 3a+6+a
9 = 4a+6
9-6 = 4a+6-6
3 = 4a
4a = 3
4a/4 = 3/4
a = 3/4
So the solution is the fraction a = 3/4 (in decimal form 0.75)
Let me know if you have any questions or issues with any of the steps shown above. It's a lot to take in so feel free to ask about anything really.
