Please solve all questions step by step​

Tanya has $42 to spend at the dolphin island store. tshirts sell for $7 each and a pair of sunglases sells for $6.tanya buys 3 tshirts. how many pairs of sunglases can she buys with the amount of money she has left

The vet charges $45 for an office visit and $10 for each vaccination your dog needs. write an eaquation

Varies inversely with x. if y=8.5 when x=-1 find x when y=-1