Question

If the slope of the line joining the points (4,2) and (3,-k) is -2, then the value of k is

• A. -3
• B. 4
• C. 3
• D. -4

Answer 1

The Correct Option is D

The slope of the line joining two points $(x_1, y_1)$ and $(x_2, y_2)$ is given by $$m = \frac{y_2 - y_1}{x_2 - x_1}$$ Here, $(x_1, y_1) = (4, 2)$ and $(x_2, y_2) = (3, -k)$. The slope is given as -2. So, $$-2 = \frac{-k - 2}{3 - 4}$$ $$-2 = \frac{-k - 2}{-1}$$ $$-2 = k + 2$$ $$k = -2 - 2$$ $$k = -4$$