What’s the answer smh

We just started the introduction into circles and i have no idea how to do this.

Simplify the expression 8h - 57-3m by adding or subtracting the like term

6. tim is trying to study but hours go by and he doesn't get anything done. what time management advice would tim? work in smaller chunks of time an hour or less whenever you have a few minutes to spare. create flashcards. talk to your instructor right away and make a plan together for how you can get back on track, take scheduled breaks only or allow yourself only 5-10 minute breaks find somewhere quiet like a library or school to study tum off your phone and/or tell others you are busy