Answer:
25.2
Step-by-step explanation:
6/5 is 1.2, so it takes 1.2 minutes to run one lap.
This means 21 x 1.2 = the minutes it takes to run 21 laps around the track.
Therefore it takes 25.2 minutes to run around the track 21 times.
5x-8y=1...(1)
3x+6y=-21...(2)
(1)*3:
15x-24y=3...(3)
(2)*5:
15x+30y=-105...(2)
(3)-(2):
15x-24y-(15x+30y)=3-(-105)
15x-24y-15x-30y=108
-54y=108
y=-2
11 g's ..That's Why Most People Say "You don't need it"