Answer:
c = 8x-30
23x-90
Explanation:
Since the cost of soda is x, 8 times the cost of soda is is 8x.
Then, you have to take 30 cents away, so the cost for pizza would be 8x-30 or 8x-.30.
This is your pizza or c.
Next, to put in 3 pizzas and 5 sodas, you just multiply 3 and 5 by the corresponding variables.
So 3(8x-30) + 5(x) = 18x - 90 + 5x = 23x - 90 or 23x - .90