You are planning to run the distance on both Thursday and Friday. Write and solve an equation to find the number of mi. you need to run each day so you run a total of 13.1 miles over the five days.
after everything you've ran the total would be 9.7 but you'll need to run a total of 13.1 so you still need to run 3.4 miles so you Thursday and Friday you'll run 1.7 each.