Translation of 4 units down.
Step-by-step explanation:
The original, or parent, function of a linear equation is y = mx + b, with 'b', being the y-intercept.
With a -4 plugged in, the intercept is at (0, -4). With this in mind, going down the graph 4 more units, will get you -8, and an intercept of (0, -8).
If you plug this in, it'd be g(x) = 5x - 8.