How to solve 2m - 3 = 13

Ineed me i stuck and i don’t want to get it wrong

Tabby sells clothing at a retail store, and she earns a commission of 6.25% on all items she sells. last week she sold a pair of jeans for $32.50, a skirt for $18.95, and 2 blouses for $14.95 each. what was tabby's total commission? a $4.15 b $5.08 c $81.35 d $348.60

Including 6% sales tax, an inn charges $135.68 per night. find the inns nightly cost