[tex]\it 0,(\overline{x1}) + 0,(\overline{x2})+0,(\overline{x3})+ ... +0,(\overline{x9}) =x[/tex]
[tex]\it \dfrac{\overline{x1}}{99} + \dfrac{\overline{x2}}{99} + \dfrac{\overline{x3}}{99} + ... + \dfrac{\overline{x9}}{99} + =x[/tex]
[tex]\it \dfrac{1}{99}( \ \overline{x1}+\overline{x2}+\overline{x3}+ ... +\overline{x9})=x[/tex]
[tex]\it 10x+1 +10x+2 +10x+3 + ...+10x+9 = 99x[/tex]
[tex]\it 9\cdot10x +(1+2+3+ ...+9) = 99x[/tex]
[tex]\it 90x +45 = 99x \Longrightarrow 45 = 99x - 90x \Longrightarrow 45 = 9x \Longrightarrow x = 5 .[/tex]
