Question 11765
You can start with the equation:

{{{30 - (k + m) = 25}}}  Add (k + m) to both sides.

{{{30 = 25 + (k + m)}}} Now subtract 25 from both sides.

{{{5 = (k + m)}}}

What are the possiblities for k and m?
k = 0 & m = 5 or
k = 1 & m = 4 or
k = 2 & m = 3 or
k = 3 & m = 2 or
k = 4 & m = 1 or
k = 5 & m = 0