I need help on this problem

1. what is the phythaforean theorem? 2.what do we use it for? 1.what is the distance formula ? 2.what do we use it for?

One line passes through (-7,-4) and (5,4) . another line passes through the point (-4,6) and (6,-9)

Bill works as a waiter and is keeping track of the tips he ears daily. about how much does bill have to earn in tips on sunday if he wants to average $22 a day? tips by day tips (dollars) monday tuesday wednesday thursday friday saturday $14 $22 $28 $36