Find the distance and the midpoint of two given points P1 and P2 below: P1 (10, 3) and P (6, 9). Please simplify your answer and using radical as needed. 15. Find the standard form of the equation of the circle with endpoints of a diameter at the points (1,4) and (-7, 6) 16. A motorboat can maintain a constant speed of 12 miles per hour relative to the water. .The boat makes a trip upstream to a certain point in 28 minutes; the return trip takes 20 minutes. What is the speed of the current