
Alla M. answered 08/29/12
Experienced Certified Math and Business Tutor
So what this question is trying to say is that 1 gallon = 98 tons of organic material
lets say f(G)="an expression for the amount (in tons) of organic material it takes to make G gallons of gas"
so this means that f(G)=98G because 98 tons is used per one gallon so we just add one G
For the second part of the question just plug in 20 where the G is.
f(20)=98*20
98*20=1960 tons
To fill a car with 20 gallons of gas it will take 1960 tons of organic material.