The total arc length around a circle is 360 degrees. So, these 3 arc with expressions given will all add up to 360.
(-2 + 8x) + (10x + 10) + (10x - 12) = 360
28x - 4 = 360
28x = 364
x = 13
Now that we know the value of x, we can plug that value into the expression for arc LM and solve for the measure.
LM = 10x - 12
LM = 10(13) - 12
LM = 118 degrees
Hope this helps! :)
