Question

Aflati divizorii lui 98 si determinati numerele naturale n stiind ca 5n-1 divide 98?

Answer 1

D98 = {1; 2; 7; 14; 49; 98}
 5n-1 divide 98 => 5n-1 =D98
5n-1={1; 2; 7; 14; 49; 98}
5n={2; 3; 15; 50; 99}
n nr natural => n={3; 10}