Is someone able to explain the process of how to find the last 2 values? ?

These question are hard can you me with answers

Danielle earns a 7.25% commission on everything she sells at the electronics store where she works. she also earns a base salary of $750 per week. what were her sales last week if her total earnings for the week were $1,076.25?

Solve the triangle. a = 21°, c = 105°, c = 5