A graph is shown with scale along x axis from 0 to 10 at increments of 1 and scale along y axis from 0 to 15 at increments of 1.The ordered pairs 0, 13 and 1, 11.5 and 1.5, 10.9 and 2, 10 and 3, 9 and 4, 8.5 and 5, 7 and 6, 5 and 7, 4 and 8, 3 and 9, 1, 9.8, 0.3 are shown on the graph. A straight line joins the ordered pairs 0, 13 and 10, 0. What is the approximate equation of this line of best fit in slope-intercept form?

y = −13x + 13 over 10
y = negative 13 over 10x + 13
y = negative 10 over 13x + 13
y = −13x + 10 over 13