PLS HELP I WILL MARK BRAINLEAST!

The fire department is having a BBQ fundraiser. The hot dogs costs $1.50 each and cans of
soda cost $0.75 each. The department uses the algebraic expression 1.50x +0.75y to calculate
customers' total expenses.

a. What does the x variable represent?

b. What does the y variable represent?

c. A family buys 7 hot dogs and 4 sodas. What are their total expenses?