55 min/10 km=5.5 min/km
5.5 min/km x 1 km/.621 mile= 5.5/.621=8.86 min/mile
The answer is D.
-16.9x + 16 is the correct answer. You have to remove the parentheses, collect the like terms, and then simplify.
A(t)=A0*(1/2)^(t/30)
where t=elapsed years
A0=initial mass at t=0.
