If B is the midpoint of AC, that means that the distances from A to B and B to C are the same. The distance from A to B is 8x + 4, and the distance from B to C is 10x - 6, so we can set these two equivalent:
8x + 4 = 10x - 6
Solving for x:
4 = 2x - 6 (subtract 8x from both sides) 10 = 2x (add 6 to both sides) 5 = x (divide both sides by 2)
Equation of a line is easy once you get the hang of it. State with the point slope form y-y2=m(x-x2) Simply plug in the points given to get the equation.
