A car averages 25 miles to the gallon. If gasoline costs $1.30 per gallon, how much does it cost to go on a trip of 1000 miles?

Let x equal what you are trying to fmd x = ($ / trip)

What will be an ideal response?

Reciprocal factors
1.30 $ / gal 1 / 1.30 (gal / $)
25 (mi / gal) 1 / 25 (gal / mi)
1000 (mi / trip) 1 / 1000 (trip / mi)
Build an equation
x ($ / trip) =1.30 ($ / gal) * 1/25 (gal / * 1000 (mi / trip)
Multiply factors
x ($ / trip) = 52 ($ / trip) Cost of trip is $52.00.