Help guys there’s no directions on how to do this and I’m not that great in math

Twenty-five percent of the customers entering a grocery store between 5 p.m. and 7 p.m. use an express checkout. consider five randomly selected customers, and let x denote the number among the five who use the express checkout.

What is the result of adding the system of equations? 2x+y=4 3x-y=6

Which of the following is an example of a rational number? a. π b. √ 9 c. √ 8 d. 3.8362319