Answer:
m = 68
Explanation:
MN bisects it or splits it in half so we know N = M, which we could also write as 8x-12 = 5x+18 because they give us those equations
once you have 8x-12 = 5x+18 you can subtract 5x from both sides, so you will get 3x-12 = 18, then you can add 12 to both sides and you will get 3x = 30. Once you have narrowed down to this you can divide three by both sides making x = 10
Now that we know x =10 we can insert it into the equation
5(10) + 18 = m
50 + 18 = m
m = 68