Hi, hope this helps :)
Answer:
a=7/2
Step-by-step explanation:
a^2-2a+2a-4-a^2+2a+3a+6=3a+9
You want to solve for "a"
1. Mover all terms on the right side to the left side setting this equation to zero.
2. Combine Like Terms
3. Divide to isolate your "a"
0.894
5b* because we have no idea what it could stand for