Point A is at -7,-7 and point M is at -6,-1 What are the coordinates of point B

Kapil needed to buy a long wooden beam. he went to two sawmills that each charge an initial fee plus an additional fee for each meter of wood. the following equation gives the price (in dollars) of a wooden beam from the first sawmill as a function of its length (in meters). p = 5+20xp=5+20x

The parabola opens: y=√x-4 (principal square root) up down right left

Hi i’m not sure how to do question 20 if u could explain how to do it that’d b great