Doughnuts are sold in bags and cartons.

A bag hold 4 doughnuts and a carton hold 10 doughnuts.

Tom buys B bags of doughnuts and C carton of doughnuts.

He buys a total of T doughnuts.

Write down a formula for T in terms of B and C

4B + 10C = T

Step-by-step explanation:

Each bag has 4 doughnuts. So, each bag that is sold contains four doughnuts. Moreover, each carton that is sold has 10 doughnuts. Thus, we put each amount for each variable respectively. Since T is the total amount of doughnuts, this is the formula.