FOSSIL FUELS: FOSSEL FUELS ARE PRODUCED BY THE DECAY OF ORGANIC MATERIAL OVER MILLIONS YEARS. TO MAKE ONE GALLON OF GAS, IT TAKES ABOUT 98 TONS IF ORGANIC MATERIAL,ROUGHLY THE AMOUNT OF WHEAT THAT COULD BE HARVESTED IN A 40 ACRE FIELD. WRITE AN EXPRESSION FOR THE AMOUNT (IN TONS) OF ORGANIC MATERIAL IT TAKES TO MAKE G GALLONS OF GAS. HOW MANY TONS WOULD IT TAKE TO MAKE ENOUGH GAS TO FILL A CAR'S 20 GALLON GAS T
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.
To fill a car with 20 gallons of gas it will take 1960 tons of organic material.