[tex]\bf \begin{array}{ccccccccc}
&&x_1&&y_1\\
% (a,b)
&&(~ 8 &,& 0~)
\end{array}
\\\\\\
% slope = m
slope = m\implies -\cfrac{3}{4}
\\\\\\
% point-slope intercept
\stackrel{\textit{point-slope form}}{y- y_1= m(x- x_1)}\implies y-0=-\cfrac{3}{4}(x-8)
\implies
y=-\cfrac{3}{4}x+6[/tex]