Question

Which value of x gives the line passing through (8, 1) and (x, -5) a slope of 3/2?

Answer 1

`(\stackrel{x_1}{8}~,~\stackrel{y_1}{1})\qquad (\stackrel{x_2}{x}~,~\stackrel{y_2}{-5}) ~\hfill \stackrel{slope}{m}\implies \cfrac{\stackrel{rise} {\stackrel{y_2}{-5}-\stackrel{y1}{1}}}{\underset{run} {\underset{x_2}{x}-\underset{x_1}{8}}} ~~ = ~~\stackrel{\stackrel{\textit{\small slope}}{\downarrow }}{\cfrac{3}{2}} \\\\\\ \cfrac{-6}{x-8}=\cfrac{3}{2}\implies -12=3x-24\implies 12=3x\implies \cfrac{12}{3}=x\implies \boxed{4=x}`