A girl can run a mile in 13 minutes. Write an expression for the number of miles she can run in 𝑥 minutes.
She can run a mile in 13 minutes and we want to know how far she would run if she ran for 𝑥 minutes. What we can say is that every 13 minutes, she would run a mile. That means that if we take the number of minutes she was running, and we divide that by 13, it would equal the number of miles the girl ran. 𝑥 divided by 13 is our expression.