Question

The points (-3, 3) and (7, q) fall on a line with a slope of -7/10. What is the value of q?

Answer 1

`(\stackrel{x_1}{-3}~,~\stackrel{y_1}{3})\qquad (\stackrel{x_2}{7}~,~\stackrel{y_2}{q}) \\\\\\ \stackrel{slope}{m}\implies \cfrac{\stackrel{\textit{\large rise}} {\stackrel{y_2}{q}-\stackrel{y1}{3}}}{\underset{\textit{\large run}} {\underset{x_2}{7}-\underset{x_1}{(-3)}}} ~~ = ~~\stackrel{\stackrel{\textit{\small slope}}{\downarrow }}{ \cfrac{ -7 }{ 10 }}\implies \cfrac{q-3}{7+3}=\cfrac{ -7 }{ 10 }\implies \cfrac{q-3}{10}=\cfrac{ -7 }{ 10 } \\\\\\ q-3=-7\implies q=-4`