One way to approach this problem is to go ahead and find the actual equation in slope-intercept form.
The slope of the line thru (3,6) and (5,4) is m = (6-4) / (3-5), or -2/2, or -1.
Subbing the known values of m, x and y, we get:
4 = -(5) + b. Then b = 9.
The correct equation (representing the data values in the table) is y = -x + 9.
