# Algebra

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A cup of coffee contains about 100mg caffeine. The exponential function A(t)=100(0.84)^t is used to calculate the amount of caffeine in a body t hours after the coffee was consumed. Find the amount of caffeine in the body after 4 hours. Can someone help with a step by step break down?

• Algebra -

yeah. plug in the value for t and use your calculator:

A(4) = 100(0.84)^4 = 100*0.5 = 50.0

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