Answer:

Explanation:
The kitten gains 1/3 lb each week.
In 1 week, it gains 1/3 * 1 lb.
In 2 weeks, it gains 1/3 * 2 lb.
In 3 weeks, it gains 1/3 * 3 lb.
In w weeks it gains 1/3 * w lb.
The kitten started at 2/3 lb, so when you add what it gains per week, you get
2/3 + 1/3 w
The function is:
