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HELP???
The concentration of a drug in the bloodstream decreased by 18% every hour. If an initial dose of 25mg. was administrated, how much of the drug remains in the bloodstream after 4 hours? After what length of time will 1% of the original dose remain???????

Respuesta :

Aliwohaish12
25×(1−0.18)^(4)
=11.30

25*0.01=25(1-0.18)^t
0.25=25(0.82)^t
0.25/25=(0.82)^t
t=log(0.25/25)/log(0.82)
t=log(0.25÷25)÷log(0.82)
t=23.21 hours

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