Answer is y = -1/3x + 3 2/3
First we find slope
y2 - y1 over x2 - x1
5-2 over -4 -5 = -3/9 or -1/3
Next we use one set of points and slope into equation
(5, 2) and slope = -1/3
y - y1 = m (x - x1)
y - 2 = -1/3 (x - 5)
y -2 = -1/3x + 5/3
add 2 to both sides to isolate y
y -2 +2 = -1/3x + 5/3 + 2
y = -1/3x + 3 2/3