When you are told to "combine like terms," you are asked to add all the same variables, then to add all the constants ("free numbers"). This is a process we use to simplify equations.

To start, look at what's in the parentheses. -(m+4) This says, "the opposite value of m+4" or "-1 times (m+4)

Solve that (using the distributive property): -(m+4)= -m-4

The next part says -3(7-m) which says, "negative 3 times (7-m)".

Solve that using the distributive property: -3(7-m)= -21+3m (Remember that a negative # times a negative # equals a positive #)

Now your new equation says: -m-4-21+3m

Now, combine like terms, meaning, add the variables (m's): -m+3m= 2m

Then combine the constants (free numbers) -4-21= -25

New equation should say: 2m-25. This is your answer.

Just remember, when you need to "combine like terms," you're taking the variables (letters) and adding them together. Then add the constants (free numbers) together.