391/5
(390+1)/5
(5*78 + 1)/5
78 + 1/5
78.2
The decimal for 4 5/8 is 4.625 the 4 represents the whole so 5/8 stays the same and you place the 4 in front of .625
Since the 100 degree angle is the same as the m + 20 degree angle, you only have to do: 100-20=80
So the answer is 80
N+15 because 15 more would mean a number plus 15
