Question

Rezolvati ex din poza

Answer 1

[tex]7x(x+1)+5y=2013\\ u.c.[x(x+1)]\in\{0,2,6\}\\ uc[7x(x+1)]\in\{0,4,2\}\\ uc(5y)\in\{0,5\}\\ uc[7x(x+1+5y]\in\{0+0,0+5,4+0,4+5,2+0,2+5\}=\\ \{0,2,4,5,7,9\}\\ u.c(2013)=3[/tex]
prin urmare nu exista numere naturale care sa indeplineasca conditia