If the pencil markings are correct, LM=NP. This means that both lines should be the same length (you've marked them as congruent). Therefore, you can set the two equations equal to one another. 3x=5x-14 You should get a solution of x=7. If you have trouble with that, comment. I was lazy and did it with my graphing calculator, but I can show you how to do it algebraically.
From the drawing, assuming your congruency markings are correct, K is the midpoint of LM. Therefore, LK will be half the length of LM. As LM looks like it equals 3x, LK would be 3x/2. In the above step, I found that x=7. Plug x unto the equation 3x/2 to get 21/2, which is your final answer.
