Respuesta :

Let number of weeks be x.

  • Frank deposits every week=$20

So the function is given by

[tex]\\ \sf\longmapsto f(x)=20x[/tex]

Balance in first month

[tex]\\ \sf\longmapsto f(1)=20(1)=20[/tex]

In second month

[tex]\\ \sf\longmapsto f(2)=20(2)=40[/tex]

And so on