Answer:
1 3/7 hours exact answer
1.43 hours decimal approximation
Step-by-step explanation:
1 brake/2hrs + 1brake/5hrs = x
to find how much they can do in the same amount of time
use common denominator of 10 hours
5brakes/10hrs + 2brakes/10 hrs = 7brakes/10 hrs
10 hrs for 7brakes = 10/7 hours for 1 brakes
1 3/7 hours to do the brakes working together
or as a decimal about 1.4285714286 hours