You can
put this solution on YOUR website!Just looking at the units:
(miles/year) / (miles/gallon) = (miles/year) x (gallons/mile) = gallons/year
given:
She drives

miles/year
Her present car gets

miles/gallon

gallons/year
The car she wants gets

miles/gallon

gallons/year
and
Gas is $

/gallon for the year
For old car:

gallons/year x

dollars/gallon =

dollars/year
For new car:

gallons/year x

dollars/gallon =

dollars/year

In the 1st year, she'll save $206.25