y = x - 4
First find the slope of the two coordinates.
Slope is the change in y over the change in x
Y2-Y1 / X2-X1
26-9 / 30-13
17/17 or 1
Now we have
y = 1x + b
To find b, plug in one of the x,y coordinates into this equation
9=1(13) + b
9 = 13 + b
Subtract 13 from each side
-4 = b
So the answer is
y=x-4
