[tex]a)\;10x=3,333...\\
~~~~~~~x=0,333...[/tex]
[tex]\Longrightarrow9x=3[/tex]
[tex]x=\dfrac{3}{9}=\dfrac{1}{3}[/tex]
[tex]0,333...=\dfrac{1}{3}[/tex]
[tex]b)\;10x=14,444...\\ ~~~~~~~x=1,444..[/tex]
[tex]\Longrightarrow9x=13[/tex]
[tex]x=\dfrac{13}{9}[/tex]
[tex]1,444...=\dfrac{13}{9}[/tex]
[tex]c)\;100x=215,555...\\ ~~~~~~~10x=21,555...[/tex]
[tex]\Longrightarrow90x=194[/tex]
[tex]x=\dfrac{194}{90}=\dfrac{97}{45}[/tex]
[tex]2,1555...=\dfrac{97}{45}[/tex]