we know that
The equation of the line in the slope-intercept form is equal to
[tex]y=mx+b[/tex]
we have
[tex]x+4y=12[/tex]
Solve for y
[tex]x+4y=12[/tex]
Subtract [tex]x[/tex] both sides
[tex]x+4y-x=12-x[/tex]
[tex]4y=12-x[/tex]
Divide by [tex]4[/tex] both sides
[tex]4y/4=(12-x)/4[/tex]
[tex]y=(12-x)/4[/tex]
[tex]y=-\frac{1}{4}x+3[/tex]
therefore
the answer is
[tex]y=-\frac{1}{4}x+3[/tex]