Congratulations! You are the proud new pup-parent of a brand new puppy! When you bring the pup for his first check-up, the vet explains to you that it's a common misconception that dogs age 7 "dog years" for every human year. Instead, he says, small breed dogs age 15 "dog years" in the first year, 9 "dog years" in the second year, and 4 "dog years" per year after that. You wonder, when will my pup and I be the same age? Your solution MUST include responses to ALL four parts. 

1. Understand the problem. (The prompt below may help you.) Today, you are __________________ years old (choose one of your ages). Your puppy is zero years old. Exactly one year from today, you will be ____________ years old. Your puppy will be 15 years old in “dog years.” Your task for this test is to determine when you and your new pup will be the "same" age. 

2. Make a plan. State your plan for solving this problem. You may use words or diagrams. You may want to consider how you can organize or represent the years that have passed since getting the puppy, your age, and the puppy’s age. 

3. Implement your plan. Once you have articulated your plan, carry out your plan. Using the information given, create a mathematical model, an equation that you can use to determine when you and your pup will be the “same” age.