Word problem

Kit bought a soft drink and a sandwich for $9.00. What was the price of each if the sandwich cost 3.5 times as much as the soft drink?

Let the cost of the soft drink = C   then the price of the sandwich was 3.5 times as much = 3.5C

And

C + 3.5C  = Total Cost

C + 3.5C  =   9

4.5C = 9    divide both sides by 4.5

C = 9/4.5  =  $2.00   for the soft drink

And  3.5C = 3.5(2.00)  = $7.00   cost of the sandwich