If you're given the slope of a line and asked to find the equation of the line, just find the intercept which can be done by plugging in the point on the line that's given to you.
An easy way to think about this is in the slope-intercept form: y = mx + b
where m = slope of the line and b = y-intercept of the line
y = (-2/3)x + b
16 = (-2/3)(-12) + b
16 = 8 + b
b = 16-8 = 8
Ans: The equation of the line is y = (-2/3)x + 8