C= 20-0.75x
c= 20-0.75(9)
c= 20-6.75
c= 13.25
Here c is the amount of change and x is the number of books bought.
The customer's change will be $13.25
Answer:
27+r
Step-by-step explanation:
Answer:
The cost of 15 liters is $31.50
Step-by-step explanation:
1. Find the price for 1 liter of petrol.
Divide the cost by the number of liters:
$14.70 / 7 = $2.10 per liter.
2. Multiply the price for 1 liter by the new number of liters, 15.
$2.10 per liter x 15 liters = $31.50
