Answer:
m∠MON = 99°
Explanation:
A "straight angle" has a measure of 180°, so the two given angles will have that value as their sum.
m∠MON +m∠LOM = m∠LON
(8x -13°) +(7x -17°) = 180°
15x -30° = 180° . . . . collect terms
x -2° = 12° . . . . . . . . divide by 15
x = 14° . . . . . . . . . . . add 2°
Now we can find the measures of the angles.
m∠MON = 8x -13° = 8(14°) -13°
m∠MON = 99°
_____
Check
m∠LOM = 7x -17° = 7(14°) -17° = 81°
The sum of 81° and 99° is 180°, as it should be.