Answer:
42°
Explanation:
Line JL and line MK intersect each other at point N and forms two pairs of vertically opposite angles.
We know, that the vertically opposite angles are equal in value.
So, ∠ JNM = ∠ KNL and ∠ JNK = ∠ MNL.
Given that, ∠ JNM = 4x + 6 and ∠ KNL = 7x - 21
Therefore, 4x + 6 = 7x - 21
⇒ 3x = 27
⇒ x = 9
So, ∠ JNM = 4x + 6 = 4(9) + 6 = 42° (Answer)