Question

Find the equation of the line through the points (0,7) and (3,−8). Enter your answer in slope-intercept form y=mx+b.

Answer 1

`(\stackrel{x_1}{0}~,~\stackrel{y_1}{7})\qquad (\stackrel{x_2}{3}~,~\stackrel{y_2}{-8}) ~\hfill \stackrel{slope}{m}\implies \cfrac{\stackrel{\textit{\large rise}} {\stackrel{y_2}{-8}-\stackrel{y1}{7}}}{\underset{\textit{\large run}} {\underset{x_2}{3}-\underset{x_1}{0}}} \implies \cfrac{ -15 }{ 3 } \implies - 5`

`\begin{array}ll \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}{7}=\stackrel{m}{- 5}(x-\stackrel{x_1}{0})\implies {\Large \begin{array}{llll} y=-5x+7 \end{array}}`