Explanation:
First, let's turn the standard form equation into a slope-intercept form equation.
*(This is an easier method)
Slope-intercept form:

m = slope
m = slopeb = y-intercept
Switch each term:

-4 becomes a negative number since the y and slope have switched.
Divide each number by 2, to simplify y:

Using the slope-intercept format, we can see 4 is in the position of the y-intercept.
Therefore, the y-intercept is 4.