A car can travel 476 miles on 14 gallons of gas. How do you write equation relating the distance d to the number of gallons g. How many gallons of gas does this car need to travel 578 miles?

Question

14958 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-05-24T01:21:34

#17" gallons"#

You are given that traveling #476# miles consumes #14# gallons of gas. You can rewrite this as a formula:

#476xxd=14xxg#

You can divide both sides by #14# to get

#476/14 d=1xxg#

#34xxd= 1xxg#

That is, #1# gallon will take you #34# miles (or #34# mpg)

This gives us a conversion factor which can be expressed in one of two ways:

Either #(34" miles")/(1" gallon")# or #(1" gallon")/(34" miles")#

If you are given gallons, use the first one. If you are given miles, use the second one. You are given miles, so

#578cancel(" miles")xx(1" gallon")/(34cancel(" miles"))=17" gallons"#