Sqrt(5/3)
and
sqrt(0/6)
many square roots are irrational numbers as long as they are not a perfect square
|-3| becomes positive 3
0.6 can be converted into a fraction 6/10
N = N₀* 
where N is how much you currently have
N₀ is the starting amount
t is the time
and h is the half life of the substance.
8.75x=61.25
x represents the hours he worked
to get (x) you have to divide both sides by 8.75
so
×=7
Jose worked for 7 hours
This sounds a lot like an obtuse triangle. I hope this helps! :)