Question

Find k, if R(1, –1), S (–2, k) and slope of line RS is –2. 

Answer 1

Slope of line RS is –2
Slope of RS will be

\[\frac{y_2 - y_1}{x_2 - x_1} = \frac{k - \left( - 1 \right)}{- 2 - 1} = \frac{k + 1}{- 3} = - 2\]

\[ \Rightarrow k + 1 = 6\]

\[ \Rightarrow k = 5\]