Răspuns :
Răspuns:
Explicație pas cu pas:
0,(a) = a/9
0,0(a) = a/90
0,00(a) = a/900
1/(a/9) + 1/(a/90) + 1/(a/900) = 9/a + 90/a + 900/a = 999/a
[tex]\it =\dfrac{9}{a}+\dfrac{90}{a}+\dfrac{900}{a}=\dfrac{9+90+900}{a}=\dfrac{999}{a}\\ \\ \\ Obs.\\ \\ \dfrac{1}{\dfrac{x}{y}}=\dfrac{y}{x}[/tex]