Question

The points (10,-7) and (-7,x) lie on the same line. If the slope of a line is 4, waht is the value of x?

Answer 1

`(\stackrel{x_1}{10}~,~\stackrel{y_1}{-7})\qquad (\stackrel{x_2}{-7}~,~\stackrel{y_2}{x}) \\\\\\ \stackrel{slope}{m}\implies \cfrac{\stackrel{\textit{\large rise}} {\stackrel{y_2}{x}-\stackrel{y1}{(-7)}}}{\underset{\textit{\large run}} {\underset{x_2}{-7}-\underset{x_1}{10}}} = \stackrel{\stackrel{\textit{\small slope}}{\downarrow }}{ 4 }\implies \cfrac{x+7}{-17}=4\implies x+7=-68\implies x=-75`