The answer is C) 8a^2 - ab + 2b + 9, I'll explain why.
So the problem is
(3a^2 + 2ab + 2b) + (5a^2 - 3ab + 9)
First, distribute the implied 1s to get rid of the parenthesis.
1(3a^2 + 2ab + 2b) + 1(5a^2 - 3ab + 9)
3a^2 + 2ab + 2b + 5a^2 - 3ab + 9
Now just simplify by adding like terms.
3a^2 and 5a^2 are like terms, because they have the same variables and exponents. Since they're like terms, we add the coefficients.
3ab^2 + 5ab^2 = 8ab^2.
2ab and -3ab are also like terms, so we again add them, or in this case subtract since -3ab is negative.
2ab - 3ab = -1ab, or just -ab.
Now we're left with 8a^2 - ab + 2b + 9.
Neither 2b nor 9 have any like terms, so we leave them alone and our final answer is 8a^2 - ab + 2b + 9.
Let me know if you're confused about anything and I'll try to explain further.
Hope this helps!
