Macy's charges $12 for an item plus a $10 shipping and handling charge for the order. What is the cost of an order of of 5 of those items? Answer pls idk get it pls

Just tell me how to set up the equation.

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?

Which equation can be solved to find x the measure of jk in the apex