You can put this solution on YOUR website! y intercept is the distance between the origin and the point where the line cuts y-axis. To get the point where a line cuts y-axis, substitute x=0 in the line equation(because every point on y-axis has its x-coordinate zero!!!)
we get -5y=20 implying y=-4
So the point is (0, -4)
Its distance from origin is 4 units.
Hence the y-intercept is 4.