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"
1. -21
2. −39
3.−42
4. -5
5. −3
for the other question u can use calculator :)
The answer to this is ten.