Question

i need help finding the expression and the problem

Fossil fuels are produced by the decay of organic material over millions of years. To make one gallon of gas it takes about 98 tons of organic material roughly the amount of wheat that could be harvested in a 40-acre field. Write 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 tank?

Answer 1

How many tons to make 1 gallon? How many tons to make 2 gallons? How about 3? What is the pattern? Can you use the pattern to realize how many tons for 10 gallons or 100 gallons, in other words, bigger than you want to count up 1 gallon at a time?

This is how you look for the expression.

Answer 2

I tried that but I still don't know the expression. Like I don't get what it is.

Answer 3

Ok, no worries. First question, what class is this for?

Answer 4

Algebra 1 9th grade math

Answer 5

Total = 98g

Answer 6

Thanks,
So, "m" is the amount of material needed to make some amount of gas, and "g" is the number of gallons of gas.
Then the expression is the "rule" to tell you how much material you need for how much gas. So,
M = 98 times "g" or 98g
Because when you put in the amount of gas you want (example, 1 gal), you get 98 x 1 = 98 tons of material. To get g=2 gallons, you need M = 98(2) = 196 tons. And so on.

Answer 7

Yes, you don't even have to give a variable name to "Total" -- that's fine to just say Total = 98g

Answer 8

By the way, the whole "40 acre field" thing is just to distract you...

Answer 9

thank you that helped me alot. :)

Answer 10

Then don't forget to do the rule for 20 gallons for the last part...

Glad to help, good luck in class :)