Roscoe's family has dinner at a restaurant. The total cost is $103.80. This includes 5% tax and 15% tip on the ore tax amount. How much was the bill before tax and tip?

Respuesta :

Answer:

  $86.50

Step-by-step explanation:

Let b represent the bill before tax and tip. Then the total is ...

  b + 0.05b + 0.15b = 103.80

  b(1.20) = 103.80 . . . . . . . . . . collect terms

  b = 103.80/1.20 = 86.50 . . . divide by the coefficient of b

The bill before tax and tip was $86.50.