Answer:
The answer is 5a-35.
Explanation:
So, since you told me to explain, if a number is right next to a parentheses without any signs you multiply it.
But instead of doing 5 times 7a, you multiply both of them separately.
5 times a is pretty much just 5a. 5 times -7 is -35.
As a result, you will be left with 5a-35.
If you have anymore questions, let me know.