we have the following:
[tex]\begin{gathered} 12x+4y=16 \\ \end{gathered}[/tex]slope intercept form is:
[tex]y=mx+b[/tex]therefore,
[tex]\begin{gathered} \frac{12}{4}x+\frac{4}{4}y=\frac{16}{4} \\ 3x+y=4 \\ y=-3x+4 \end{gathered}[/tex]slope (m)= -3
y-intercept (b) = 4