Answer:
1. You Identify like terms by whether they are connected to a similar value. (2x and 7x are examples of like terms, having both be connected to an X value.)
2. 2n and 10p are not like terms. As they both are connected to differing values
3. 8a+20 (multiply the variables inside the parenthesis by whatever is on the outside of the parenthesis)
4. The coefficient is the constant quantity connected to a value. In this case the coefficient is 7.
Explanation:
Stop answering questions you don't know the answer to. It helps nobody and wastes points that could have very well been given to someone that actually answered/deserves them.