Because m and n are whole numbers, we only have 3 values for m, and 3 values for n :
[tex]1^{121} ; 11^{11} ;121^{1}[/tex] (or you can say because 121 only have the factors of 1 ; 11 ; 121, those are the only possible values for m and n, then conclude the possible values)
Now, we will substitute them in :
If m = 1 ; n = 121
[tex](1-1)^{121+1}[/tex] = 0
If m = 11 ; n = 11
[tex](11-1)^{11+1}[/tex] = 1000000000000
If m = 121 ; n = 1
[tex](121-1)^{1+1}[/tex] = 14400
