Explanation:
since we have the slope and a point, let's start with the point-slope form first, and then we transform it into the slope-intercept form.
the general slope-intercept form is
y = ax + b
"a" being the slope and b the y-intercept (the y-value when x = 0).
the general point-slope form is
y - y1 = a(x - x1)
"a" is again the slope, (x1, y1) is a point on the line.
so, in our case
y - -16 = -2(x - 6)
y + 16 = -2x + 12
y = -2x - 4
that's it.