The parentheses inside gives you - 5 because you are subtracting an integer, so you flip the sign to addition and change the sign to the opposite number which is -. The 6 squared is 36.
This may or may not go by GCF, or Greatest Common Factor. But though is may actually go by just solving. First you multiply your 6 squared, to get 36. Then, you add what’s inside the parentheses. Your equation should now be 36x5-3, -5 is just like 0+5. Multiply 36x5 tiger 180-3. Your final answer would be 177.