Evan takes 100 milligrams of medicine. The amount of medicine in his bloodstream decreases by 0.4 milligram each minute for a number of minutes, m, after that. He writes the expression 100 – 0.4m to find the amount of medicine in his bloodstream after m minutes. Which statement about his expression is true?
It is the product of the initial amount and the amount of decrease each minute, m.
It is the difference between the initial amount and the amount of decrease after m minutes.
It is the product of the initial amount and the amount of decrease after m minutes.
It is the difference between the initial amount and the number of minutes, m.