The deli at the local grocery store sells chicken for $3.80 per pound, beef for $3.50 per pound, and salami for $2.90 per pound. Write an expression that shows how much it will cost to buy c pounds of​ chicken, b pounds of​ beef, and s pounds of salami.​ Then, find the cost for 1 pound of​ chicken, 1.8 pounds of​ beef, and 3.2 pounds of salami. The cost of 1 pound of​ chicken, 1.8 pounds of​ beef, and 3.2 pounds of salami is ​$_