Question

how much gas do you use to travel 172 miles at 4.00 a gallon.

Answer 1

Your question doesn't make any sense. Some vehicles get 10 miles per gallon; others get up to 40 miles per gallon. The price per gallon doesn't give any indication about how much gas is used.

Please clarify.

Answer 2

If you're asking about 4 miles per gallon -- divide 172 by 4.