To find the equation of the line passing through two points, you can use the point-slope form of a line. The slope of the line is given by the formula m = (y2 - y1) / (x2 - x1), where (x1, y1) and (x2, y2) are the coordinates of the two points. In this case, the slope is m = (5 - 15) / (4 - (-6)) = -10/10 = -1.
The point-slope form of a line is y - y1 = m(x - x1), where (x1, y1) is one of the points on the line and m is the slope. Substituting in the values for m, x1, and y1, we get y - 15 = -1(x + 6). Simplifying this equation gives us y = -x + 9.
So, the equation of the line passing through the points (-6, 15) and (4, 5) is y = -x + 9.