First: we must find the equation of the line passes through the points (-3, 0) and (0,6).
The slope-intercept form:

m - slope
b - y-intercept → (0, b)
Therefore we have b = 6.
Calculate the slope:

We have the equation of the line l: y = 2x + 6.
The equation of the graph in attachment is |y|.
Answer: y = |2x + 6|