Question 1018497
 
{{{m+np^2=5m-np^2=12}}}

{{{system(m+np^2=12,5m-np^2=12)}}}

let {{{x=np^2}}}

{{{system(m+x=12,5m-x=12)}}}

Solve that and get 

{{{m = 4}}}
{{{x = 8}}}
{{{np^2=8}}}

The only whole number solution is when p=n=2

So m=4, n=2, p=2 are the only whole number solutions.

Edwin</pre>