I can't do this question, and don't have the answer to refer to, could someone work this out?

If i purchase a product for $79.99 and two accessories for 9.99 and 7.00 how much will i owe after taxes applies 8.75%

Katie wants to collect over 100 seashells. she already has 34 seashells in her collection. each day, she finds 12 more seashells on the beach. katie can use fractions of days to find seashells. write an inequality to determine the number of days, dd, it will take katie to collect over 100 seashells.

Solve for b. ab + c= d b= a + old ob=allc-ch b= (d-c/a