Answer: 13
Step-by-step explanation:
5+2x
When x=4
5+2(4)
5+8
= 13
First you have to figure out the length of the track:

r is the half of the diameter:
200ft : 2 = 100ft

= 200

≈
628,31
The athlete has to run ca. 5280ft for one mile:
5280 : 628,31≈8,4
The athlete has to run 8,4 laps
LCM is found by finding the factors of both and making sure that both are inthere
9=3 times 3
12=2 times 2 times 3
common one is 3
so we have to have at least 2 threes and 2 twos
2 times 2 times 3 tiimes 3=36
answer is 36