Question

Ajutor a=[tex]a=(3 21 +3 ^{20} +3 ^{19} ):39 este  cp 
b=(5 ^{62} +5 ^{61} +5 ^{60} )*961 e  pp[/tex]

Answer 1

$a=(3 ^{21}+3 ^{20}+ 3^{19}) :39= \\ ~~~= 3^{19}( 3^{2}+3+1):39= \\ ~~~= 3^{19}*13:13:3= \\ ~~~=3 ^{18}= \\ ~~~=(3^{9} )^{2} -patrat~perfect.$

$b=(5 ^{62}+ 5^{61}+5^{60})*961 = \\ ~~= 5^{60}(5^{2}+5+1) *31 ^{2} = \\ ~~= ( 5^{20} ) ^{3}*31* 31^{2}= \\ ~~= (5^{20})^{3}*31^{3}= \\ ~~=(5 ^{20}*31)^{3}-~cub~perfect$