We have the following expression:
[tex]y=-16(-\frac{1}{4})x-1[/tex]The function form is in the form f(x)= mx +b, so we can write:
[tex]f(x)=-16(-\frac{1}{4})x-1[/tex]If we make the product on the left hand side of x, we get
[tex]-16(-\frac{1}{4})=16\cdot\frac{1}{4}=\frac{16}{4}=4[/tex]then, our function form is
[tex]f(x)=4x-1[/tex]