To solve each of these equations, we need to simplify each expression step by step.

1) 2m + 235 + 4m - 125 - 5m = 19980
Combine like terms:
2m + 4m - 5m = m
235 - 125 = 110
So the equation becomes: m + 110 = 19980
Subtract 110 from both sides:
m = 19870

2) (7x - 15) = 54
Add 15 to both sides:
7x = 69
Divide by 7 on both sides:
x = 9

3) 285 - (x/14) - 481 = 36*6
Divide x by 14:
285 - (x/14) - 481 = 216
Combine like terms:
285 - 481 = -196
Substitute -196 into the equation:
-196 - (x/14) = 216
Multiply by 14 on both sides:
-2744 - x = 3024
Add x to both sides:
-2744 = 3024 + x
Subtract 3024 from both sides:
-5768 = x

4) 3 (7 + 42) - 8x = 4041
Calculate the inner parentheses first:
3 49 - 8x = 4041
Multiply:
147 - 8x = 4041
Subtract 147 from both sides:
-8x = 3894
Divide by -8:
x = -486.75

So the solutions are: m=19870, x=9, x=-5768, x=-486.75.