To combine like terms, we separate our constants from our variables. As you can see, if we are not given a variable value, you cannot combine 7x and 5. They are not like terms. However, you could combine 7x and -5. Note that combine does not always mean to add. If you combine a negative number, you subtract.
First, let's combine the whole numbers. Note that to find our operation, we use the operation before the second number. In this case, we subtract 17.
Combining like terms is pretty simple. First, you would identify which terms are similar to what terms. For example, you can't combine two terms that aren't similar like 2x and 3y. It would have to be 2x and 3x to combine. Next, be sure to add/multiply/subtract/divide/etc. the terms. For example, if you had the problem 2x + 4x + 3y, you would combine the "x" terms and the resultant problem would be 6x + 3y. Hope this helped :)
