Math
posted by Teri .
Gasoline is about $2 per gallon. You use about gallons each day driving to and from work. How much should you budget for gasoline over the next month (about 20 workdays)?

You left off the number of gallons. I call it x
I assume x is for the round trip, although that is stated ambiguously.
then you use 20 x gallons/month
2 $/gallon * 20 x gallons/month = 40 x $/month 
Thanks Damon, I have tried and tried that one but for some reason it just not look right.