[tex]\bf \begin{array}{ccccccccc}
&&x_1&&y_1&&x_2&&y_2\\
% (a,b)
&&(~ -6 &,& -5~)
% (c,d)
&&(~ -8 &,& -7~)
\end{array}
\\\\\\
% slope = m
slope = m\implies
\cfrac{\stackrel{rise}{ y_2- y_1}}{\stackrel{run}{ x_2- x_1}}\implies \cfrac{-7-(-5)}{-8-(-6)}
\\\\\\
\cfrac{-7+5}{-8+6}\implies \cfrac{-2}{-2}\implies 1[/tex]
[tex]\bf \stackrel{\textit{point-slope form}}{y- y_1= m(x- x_1)}\implies y-(-5)=1[x-(-6)]
\\\\\\
y+5=1(x+6)\implies y+5=x+6\implies y=x+1[/tex]
