A study was conducted on how a certain nutritional supplement affects weight loss. The table and graph above show the weight \(w\), in pounds, of a single male subject \(t\) days after he began taking the supplement.

The rate at which the subject’s weight is changing from day 10 through day 40 is nearly constant. On this interval, which of the following equations best models the weight \(w\), in pounds, of the subject \(t\) days after the subject began using the supplement?