Please help with this one word problem

Question

Sam and Leo are selling small and large doughnut boxes for a fundraiser. Sam sold 3 small doughnut boxes and 14 large doughnut boxes for a total of $203. Leo sold 11 small doughnut boxes and 11 large doughnut boxes for a total of $220. How much does a small doughnut and a large doughnut box cost?

1. Assign Variables:
2. Let,

________ represent __________________________

________ represent __________________________

1. Write both equations for the system:
2. Sam:_____________________________

Leo:______________________________

1. Select a method:
2. Equal Values
3. Substitution 
4. Elimination 

1. Solve the system:

1. How much does a small and large doughnut box cost?

Answer 1

3S+14L = 203

33S + 154L = 2233 Equation I

11S+11L = 220

33S + 33L = 660 Equation II

subtract Equation II from Equation I to get

121L = 1573

L= 1573/121 = 13 large boxes

3S = 203-14(13) = 21

S=21/3 = 7 small boxes