Step 1: Find slope
m = (y1-y2) / (x1-x2)
m = (3-0) / (0-7)
m = -3/7
Step 2: Using this equation (y -y1) = m(x -x1); replace m with slope value -3/7 and use any of the given points and replace it with (x1, y1).
(y - 0) = -3/7 (x - 7)
Step 3: Solve for y.
y - 0 = (-3x)/7 + 3
y = (-3x) /7 + 3
