9514 1404 393
Answer:
78
Explanation:
The base (JL) is twice the length of the midline (MN), so you have ...
4x +34 = 2(5x -16)
4x +34 = 10x -32 . . . eliminate parentheses
66 = 6x . . . . . . . . add 32-4x
11 = x
Then the length of JL is ...
4(11) +34 = 78