### Home > A2C > Chapter 7 > Lesson 7.2.3 > Problem 7-127

7-127.

Ryan has the chickenpox! He was told that the number of pockmarks on his body would grow exponentially until his body overcomes the illness. He found that he had

Ryan decides to find the exponential function that passes through the points

and . Use these points to write the equation of his function of the form . Substitute both points into the equation

and solve forand.According to your model, what day did Ryan get his first chickenpox pockmark?

, or October 22