We have the following:
The equation in slope and y-intercept form is
[tex]y=mx+b[/tex]where b is y-intercept
Now, we solve the equation given in the statement and solve for y
[tex]\begin{gathered} 2x+4y=8 \\ \frac{2}{4}x+\frac{4}{4}y=\frac{8}{4} \\ \frac{1}{2}x+y=2 \\ y=-\frac{1}{2}x+2 \end{gathered}[/tex]therefore, the y-intercept is 2