Please help I really don’t get these!

If the endpoints of the diameter of a circle are (8, 6) and (2,0), what is the standard form equation of the circle? a) (x + 5)2 + (y + 3)2 = 18 (x + 5)2 + (y + 3)2 = 3.72 (x - 5)2 + (y - 3)2 = 18 d) (x - 5)2 + (y - 3)2 = 32

Sole the equation 6n + 9 = -3n - 21 - 6 for n

The statement tan theta= -12/5, csc theta=-13/12, and the terminal point determained by theta is in quadrant two