Respuesta :

irspow
Point-slope form is:

(y-y1)=m(x-x1)

So we first need to find the slope, m, which is (y2-y1)/(x2-x1)

m=(11-9)/(-1-1)=2/-2=-1, and we can use either point for y1 and x1, I'll use (1,9)

(y-9)= -1(x-1)