Cathy's a repair technician for a phone company. Each week, she receives a batch of phones that need repairs, the number of phones that she has to left to fix at the end of each day can be estimated with the equation. P is equal to 108 minus 23 d, where p is the number of phones left, and d is the number of days she has to work that week. What is the meaning of the value 108 in this equation? What a brilliant question. Okay.

So they're really told us that d is the number of days she has worked that week. So every day that she works, she has less and less phones to fix. Why? Because we have a minus sign here. But what if she hasn't worked a single day of that week? What is the value of d?

Well, D is just going to be zero, meaning this whole thing is going to be gone. And the number of phones that she has to do at the beginning of that week, given that she hasn't started a day of the week is 108. So that means Kathy starts each week with 108 phones to fix. That's a lot of fun.