Find an equation of the plane through the three points given: P = (4,0,0), Q = (6, -1, 1), R = (7,4, -1) = -12

Use a system of linear equation to find the parabola y=ax2+bx+c that passes through the points (1,2), (0,1) and (2,6)

Find the equation of the line perpendicular to the line y=3 and passing through the midpoint of the segment joining 2, 4 and -6, 10.

Is the point (3,0) on the x-axis or y-axis? How do you know?