Point-slope is the general form y-y₁=m(x-x₁) for linear equations. It emphasizes the slope of the line and a point on the line (that is not the y-intercept).
Answer is Ax+By=C. ... A, B, C are integers (positive or negative whole numbers)
Since the acceleration is a constant negative it has an absolute maximum value for y(x), thus it opens downward, as x decreases without bound as x approaches ±∞