Answer:
4
(0,4)
Explanation:
The y-intercept is the y-value for when the line intersects with the y-axis. Another way to put this is also the y-value when x=0. This is easy to find when you have a graph because you can simply look to see where on the graph the line intersects with the axis. If you don't have the graph then you can plug 0 in for x in the equation and solve.