John ran ob the treadmill for 9 2/3 hours later john rode the exercise bike for 2 4/7 hours how many hours did john do physical activity

He did physical activity for 12 5/21 hours.

im not sure

step-by-step explanation:

answer:   x = 3 + √11     and     x = 3 - √11

step-by-step explanation:

x² - 6x + 9 = 11

(x - 3)² = 11

x - 3 = ±√11

    x = 3 ± √11

x = 3 + √11     and     x = 3 - √11