Answer:
20n+15
Step-by-step explanation:
First, you need to use the distributive property to multiply 3 to the numbers inside the parenthesis.
After distributing:
8n+15+12n
Then, you combine like terms which are 8n and 12n.
To combine like terms, you either add or subtract but in this case, you add.
Now you get
20n+15
