Write a linear equation or inequality for each problem that follows, and use it to find the solution.
11. Bob has $112 more than Martha. If they have $500 in total, how much does each person have?
12. Michael is laying carpet in a perfectly rectangular hall. The area of the hall is 240 square feet, and the width of the hall is 6 feet. How long is the hall?
13. Alex bought new jeans. She paid $43.20 at the cash register, which included 8% sales tax. What's the cost of the jeans before tax?
14. Alexandra and Stephanie are sisters, and they're saving their money to buy a used car. Together they have more than $2,500, and Alexandra has $700 more than Stephanie. How much money does Stephanie have?
15. Susan took her family out for dinner. She spent less than $108 in total after tipping the waitress 20% of the bill. How much was the bill, not including the tip?
