It's grossly unfair to others, and unrealistic, to post all of your questions at once. Please, be reasonable and post no more than one or two at a time. Thank you.
Mr andrews paid less than 50 cents more per gallon of gas, x, this week, when he paid $2.50 per gallon. How much was gas this week?
If gas was priced at x LAST week, and he paid less than 50 cents more per gallon of gas THIS week, then the price of gas THIS week was x < $2.50 + $0.50.