What is the answer worked out 14b=-56

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

David is spreading mulch on a triangular area of his flower bed. the coordinates of the vertices of the area are (1, 3), (9, 3), and (4, 6). what is the area of the triangle if each square has an area of 3 square feet?

Put the equation in slope intercept form by solving for y