How do you find the value of 10 with a 4 in the upper corner

Fiona races bmx around a circular dirt course. if the radius of the course is 70 meters, what is the total distance fiona covers in two laps of the race? a. about 30,772 meters b. about 15,386 meters c. about 879.2 meters d. about 439.6 meters e. about 219.8 meters23 points hurry

The verbal translation for the difference of m and 7 increased by 15

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?