Respuesta :

FaridRjb

The answer to the first question:

[tex]\frac{28/100}{72/100}=\frac{7}{18}=\frac{7}{n}\\ n=18[/tex]

The answer to the second question:

[tex]a_{n}=a_{1}+d(n-1)\\d=a_{2}-a_{1}\\\\d=9\\a_{1}=11\\a_{n}=11+9(n-1)[/tex]