Write an equation and solve it.
Kayla purchased 5 large sodas at the movie theater. Before tax was added, the total cost of the 5 sodas was equal to the coast of 3 sodas plus $7. What was the cost of one soda, s?
Let s be the cost of one soda.
The equation can be written as 5s = 3s + 7.
Subtracting 3s from both sides gives 2s = 7.
Dividing both sides by 2 gives s = 3.5.
Therefore, the cost of one soda is $3.5.