Abigail, Alexander, and Christopher had a challenge to see who could bike the farthest in one day. Abigail biked 9 miles, Alexander biked 4 times as many miles as Christopher and Christopher biked 3 times as many
miles as Abigail. How many miles did Alexander bike?

Afarmer has a large field that is x feet in length. he wants to fence in a rectangular section in the middle of the field , leaving a length of 100 feet of open field behind each end of the fenced rectangle. he also wants the width of the fenced-in space to be 100 feet less than its length. find the expressions to represent the length and width of the fenced section of the field