The more analytic way of doing this once you get the two eqautions follows.
We have the equations of the two lines from qbkr21:
These lines have different slopes and will thus intersect at a point. The point satisfies BOTH line equations. So the two x values in the two equations are the same and the two y values in the two equations are the same. So since y = y...
We can now substitute this x value into either line equation and find that
So the coordinates of your point of intersection is