Help me write the step by step for the use of linear equation from the following:
A vehicle that gets 30 MPG will cost you $903 less to fuel each year than one that gets 20 MPG (assuming 15,000 miles of driving annually and a fuel cost of $3.61).
Over a period of 5 years, the 30-MPG vehicle will save you $4,515.
Gal. = 15000mi/30mi/gal = 500.
C = (15000/M)P*T
C = Cost.
15000 miles = Distance.
M = Mileage in miles per gallon.
P = Price per gallon.
T = Time in years.
C = (15000/30)3.61*1 = $1805.
C = (15000/20)3.61*1 = $2707.50.
Savings = 2707.50 - 1805 = $902.50/yr.
902.50/yr * 5yrs. = $4512.50.