Răspuns:
[tex]x \in \Big\{35;36;37;38;39;40;41\Big\}[/tex]
Explicație pas cu pas:
[tex]x : 7 = 5 \: rest\: r, r < 7\\ x = 7\cdot 5 + r = 35 + r \\ \\ r = 0 \iff x = 35\\ \\ r = 1 \iff x = 36 \\ \\ r = 2\iff x = 37\\ \\ r = 3 \iff x= 38 \\ \\ r = 4 \iff x = 39\\ \\ r = 5\iff x = 40\\ \\ r = 6 \iff x = 41 \\ \\ x \in \Big\{35;36;37;38;39;40;41\Big\}[/tex]