Answer:
10a
Explanation:
In this expression, when simplifying, it is key to always combine like terms.
In this case, as every term has a variable of ‘a’, you can add together the coefficient of ‘a’. A coefficient is a number infront of a variable (it can also sometimes be a variable).
Also in this expression, you might be wondering why you got the solution 9a instead.
The first ‘a’ in this expression seems as if it has no coefficient, but it actually does! It has a one in front of it! Because 1 time ‘a’ should be equal to ‘a’.
Therefore, your final answer is 10a.
Happy Learning :D
(Note :You can only do this when they have the same variable)