Question

Write an equation of the line in point-slope form through each pair of points (9,5) and (8,2)

A) y+5=3(x+9)
B )y+5=1/3(x+9)
C) y-5=3(x-9)
D) y-5=1/3(x-9)

Answer 1

`\bf (\stackrel{x_1}{9}~,~\stackrel{y_1}{5})\qquad (\stackrel{x_2}{8}~,~\stackrel{y_2}{2}) ~\hfill \stackrel{slope}{m}\implies \cfrac{\stackrel{rise} {\stackrel{y_2}{2}-\stackrel{y1}{5}}}{\underset{run} {\underset{x_2}{8}-\underset{x_1}{9}}}\implies \cfrac{-3}{-1}\implies 3 \\\\\\ \begin{array}c \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_1=m(x-x_1) \\\\ \cline{1-1} \end{array}\implies y-\stackrel{y_1}{5}=\stackrel{m}{3}(x-\stackrel{x_1}{9})`