How to get 75 using the numbers 7,5,6,and 3 only once

To get 75 using 7, 5, 6, and 3 only once:

= (7+5) * 6 + 3
parentheses first

= 12 * 6 + 3
multiplication before addition

= 72 + 3
= 75

Without being given any constraints, I'm assuming multiplication and addition were allowed.

Hope this helps! :)