Answer:
For 100 miles he uses 3.571 gallons of gasoline.
In equation form it is y/x*100
Step-by-step explanation:
Unitary Method
He travels 28 miles per gallon of gasoline.
For 1 mile he uses 1/28 gallons
For 100 miles he uses 1/28 * 100= 100/28= 3.571 gallons of gasoline.
Let x be the miles and y be the gallons of gasoline used to travel x miles.
Then for 1 mile the gallons of gasoline used will be y/ x gallons.
For 100 miles the gallons of gasoline used will be y/x *100 gallons.
In equation form it is y/x*100 gallons for 100 miles where x is the number of miles and y is the amount of gallons.