Prove that the square of an interger is not of the form 3n+2 where n is an integer

Elena and her husband marc both drive to work. elena's car has a current mileage (total distance driven) of 15,000 and she drives 23,000 miles more each year. marc's car has a current mileage of 46,000 and he drives 9,000 miles more each year. will the mileages for the two cars ever be equal? explain.

Which compound inequality could be represented by the graph?

Use sigma notation to represent the following series for 9 terms.