A pair of athletic shoes costs ​90$. If the inflation rate remains constant at 4​%, write an algebraic rule to determine the​ cost, c(t), of the shoes after t years. ​c(t) = REALLY NEED THIS ANSWER

You’re ordering more thread for blue jeans co. you usually purchase from ted’s threads, which sells 12 thread spools for $27. you recently received a notice from wade's wares that says you can buy thread from them for $2.30 each for the first 2 dozen and $2 a spool thereafter. you need to order 5 dozen spools. what percentage can you save by going with wade’s wares?