Question

Buna seara! Ma puteti ajuta cu aceasta problema?

Answer 1

3n+1=21p+13 <=> 3n=21p+12 <=> n=7p+4 si. 7m-1=21p+13 <=> 7m=21p+14 <=> m=3p+2 <=> n=x-1 /3 si m=x+1 /7 => concluzia si anume pentru A={x natural/ n natural a.i. x=3n+1} respectiv B={x natural/ m natural a.i. x=7m-1} => A int. B={x natural/ p natural a.i. x=21p+13} .