Given:
[tex]\begin{gathered} f(0)=-4 \\ \text{slope of f= -6} \end{gathered}[/tex]F(0) represents the y-intercept of the function
The general linear function has a form:
[tex]f(x)=m\cdot x+b[/tex]Where m is the slope and b is the y-intercept
So,
[tex]\begin{gathered} m=-6 \\ b=-4 \end{gathered}[/tex]Substitute with m and b, the answer will be:
[tex]f(x)=-6x-4[/tex]