Answer:
16
Step-by-step explanation:
Add 13 both sides
That would give you 5v=80
Divide 80 by 5. So v would equal 16
Two decimals equivalents to 5.000 ; 5.0 and 5
Alright
so equation is

P=initial amount
and t=time
r=rate
given
initial amount is 50
rate is 10%, but decreasing by 10% so -0.1
and time=6


A(6)=27.4406
about 27mg