Hey there!
We'll first clear up all the signs. If you're adding a negative, you're just subtracting. Therefore, we have:
5 - 2 - 14 = -2-7
Clear up left side:
-21 = -2-7
Simplify right side to get:
-21 = -9
However, this isn't a true statement. If there was a missing variable, let me know and I'd be happy to help you.