Answer :
The amount of aspirin that will be present in the patient's body after two hours is 281.25 milligrams.
How to evaluate a given mathematical expression with variables if values of the variables are known?
You can simply replace those variables with the value you know of them and then operate on those values to get a final value. This is the result of that expression at those values of the considered variables.
For this case, we have:
Amount of aspirin in a person's body (in milligrams) after t hours of taking the medicine is:
[tex]a = 500\times(\dfrac{3}{4})^t[/tex] (in milligrams)
For t = 2 hours, we get:
[tex]a = 500\times(\dfrac{3}{4})^2 = 281.25 \: \rm milligrams[/tex]
Thus, the amount of aspirin that will be present in the patient's body after two hours is 281.25 milligrams.
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