Answer:
x = 13
Step-by-step explanation:
The sum of angle measures in a triangle is 180°.
m∠M + m∠L + m∠N = 180°
(4x-4)° + (3x+12)° + (6x+3)° = 180°
13x +11 = 180 . . . . . . collect terms, divide by °
13x = 169 . . . . . . . . . subtract 11
x = 13 . . . . . . . . . . . . . divide by 13
