# How do you find the slope of the line through f (-4) =1 and f (-1) =-3?

Jul 19, 2015

Use the formula for slope to find slope = $- \frac{1}{2}$

#### Explanation:

If a line passes through points $\left({x}_{1} , {y}_{1}\right)$ and $\left({x}_{2} , {y}_{2}\right)$ then its slope $m$ is given by the formula:

$m = \frac{\Delta y}{\Delta x} = \frac{{y}_{2} - {y}_{1}}{{x}_{2} - {x}_{1}}$

In our case, let $\left({x}_{1} , {y}_{1}\right) = \left(1 , - 4\right)$ and $\left({x}_{2} , {y}_{2}\right) = \left(- 1 , - 3\right)$.

Then

$m = \frac{- 3 - \left(- 4\right)}{- 1 - 1} = \frac{1}{- 2} = - \frac{1}{2}$