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 say the cost of one soda is s dollars.
The total cost of the 5 sodas before tax is 5s dollars.
The total cost of 3 sodas before tax is 3s dollars.
From the problem, we know that the total cost of the 5 sodas equals the coast of 3 sodas plus $7. So, we can write the equation as:
5s = 3s + 7
Subtracting 3s from both sides, we get:
5s - 3s = 7
2s = 7
Dividing both sides by 2, we get:
s = 7/2
s = $3.50
Therefore, the cost of one soda is $3.50. Answer: \boxed{3.50}.