QR is congruent to PS
So if QR is 17.7 PS is 17.7
Answer 3.) PS equals 17.7
Since he has to give 50, and 12.25*p is the amount of money he has to spend (since it's 12.25 per pizza), we have 50-12.25=change
The slope-point formula:

We have (0, 3) and (-10, 4)
Substitute:

Is is it a function Bcoz 4 and 0 has only one out. When you have one in and two out that's means is not a function.