Slope:-
[tex]\\ \sf\longmapsto m=\dfrac{9+1}{9+1}[/tex]
[tex]\\ \sf\longmapsto m=\dfrac{10}{10}=1[/tex]
Equation of line in point slope form
[tex]\\ \sf\longmapsto y-y_1=m(x-x_1)[/tex]
[tex]\\ \sf\longmapsto y+1=1(x+1)[/tex]
[tex]\\ \sf\longmapsto x-y=0[/tex]
