Giải thích các bước giải:
Ta có :
$2\equiv -1(mod\quad 3)\rightarrow 2^{1975}\equiv (-1)^{1975}\equiv -1(mod\quad 3)$
$5\equiv -1(mod\quad 3)\rightarrow 5^{2010}\equiv (-1)^{2010}\equiv 1(mod\quad 3)$
$\rightarrow 2^{1975}+5^{2010}\equiv -1+1\equiv 0(mod\quad 3)$
$\rightarrow 2^{1975}+5^{2010}\quad\vdots\quad 3$