7. Madeline has a headache and takes 500 milligrams of a pain reliever. The brand of pain reliever she takes has a half-life of 2.5 hours. Which function could be used to describe the amount of pain reliever remaining in Madeline's system at any given time? F(x) = 500.1 O f(x). x= = 3(500) * O F(x) = 5 * 500 o = F(x) = 500 ()​