y = -1/2x - 7/2
Find the slope by diving the change in y by the change in x:
(-5+4)/(3-1) = -1/2
m = -1/2
To find b, or the y intercept, you can either eyeball it on the graph or plug in one of the ordered pairs into the equation:
y = -1/2 x + b
Let’s use (1,-4):
(-4) = -1/2 (1) + b
-4 = -1/2 + b
-4 + 1/2 = b
-3 and 1/2 = b
-3 and 1-2 is also equal to -7/2, so
b = -7/2
And finally:
y = -1/2x - 7/2