Explanation:
it is a line (as the variable x is only occurring with the exponent 1, this makes this a linear equation or simply a line).
all we need to do is find 2 points, mark them in the graph, and the draw a line through both points (and beyond these points).
the first point for me is always for x = 0.
f(0) = 4×0 - 4 = -4
so, the first point is (0, -4)
and for a second point let's pick e.g. x = 2
f(2) = 4×2 - 4 = 4
so, this second point is (2, 4).