## Elementary Geometry for College Students (7th Edition)

(1, -1) and (2, -2) x1=1, y1=-1,x2=2,y2=-2 Using slope formula m = $\frac{y2-y1}{x2-x1}$ m= $\frac{-2-(-1)}{2-1}$ =$\frac{-1}{1}$ =-1