i used the guess and test method…
ZK is estimated to be about >90 degrees and <135 degrees, so (9x - 24) should be between that range.
If we use 14, the answer would be 102. Subtract that from 180 and you will get 78, which equals to the angle opposite of ZK.
When adding ZL and ZM, you get 7x + 4. Using 14 again (to test if its ‘x’) in the above equation, you get 102. Then, you add it with 78 to see the total degrees in the triangle, which is 180. 102 + 78 is indeed 180.
Therefore, x = 14.
ZL is x + 9
14 + 9 = 23
ZL = 23 degrees