Answer:
m/g = 89 degrees
Explanation:
all angles in a triangle add up to 180. Therefore, make add all of the equations and make it equal to 180. 
3x + 25 + x + x - 5 = 180 
5x + 20 = 180 
5x = 160 
x = 32 
Then plug in 32 for the x in m/g to get the degrees for the angle 
3(32) + 25 
64 + 25 
89