Intersecting lines create identical vertical angles. So set the two equations equal to each other.
In other words, with intersecting lines, the angles opposite the intersection (across the "X") are called vertical angles, and they are identical.
Therefore JNK = MNL and KNL = JNM.
So set KNL = JNM:
3(x+14) = 5x+2
3x+42 = 5x+2
3x+42 -42 = 5x+2 -42
3x = 5x -40
3x -5x = 5x-5x -40
-2x = -40
-2x/-2 = -40/-2
x = 20
Now plug that into x for KNL:
KNL = 3(x+14) = 3(20+14) = 3(34) = 102°
