Respuesta :

Answer:

[tex]4[/tex]

Step-by-step explanation:

Tiana's sister age is [tex]x[/tex].

Tiana's age is:

[tex]\frac{2}{5} x[/tex]

Adding their ages gives [tex]14[/tex].

[tex]x+\frac{2}{5} x=14[/tex]

[tex]1.4x=14[/tex]

[tex]\frac{1.4x}{1.4}=\frac{14}{1.4}[/tex]

[tex]x=10[/tex]

Put [tex]x[/tex] as [tex]10[/tex]:

[tex]\frac{2}{5} (10)=4[/tex]

Therefore, Tiana is 4 years old.