Calculate the slope of the line using two different pairs of points

Acircle has a diameter will endpoints of (-2,8) and (6, 4). what is the center of the circle

The volume of a box varies directly with its length if a box in the group has a length of 30inches and k=24 what is its volume

Oliver had $50 on the day before his birthday. after he recived some money for his birthday , he had $75. write and solve eqaution to find how much money oliver received for his birthday. x+50=75