The point slope form is y-y1 = m(x-x1).
In your case, you have a slope of -5/7, so that gives you
y - y1 = -5/7 (x - x1)
Since you didn't have a graph included or state the point the graph needs to go through, I have to leave that last step to you, to plug in the x and y-values for the point in for x1 and y1.
y - (fill in y1 here) = -5/7 (x - (fill in x1 here) )