First find the slope of the line connecting these two points:
6-5
m = ------------ = -1/2
-4+2
Substitute this slope into y = mx + b: y = (-1/2)x + b.
Next, subst. 5 for y and -2 for x, and find b:
5 = (-1/2)(-2) + b, or 5-1=b. Then b = 4, and
the equation of the line is y = (-1/2)x + 4.