# What is the equation of the line with slope  m= -1  that passes through  (-1,1) ?

Jan 1, 2016

$y = - x$

#### Explanation:

Using

$y - b = m \left(x - a\right) \text{ }$, where

$m = - 1 \text{ }$ and $\text{ } \left(a , b\right) = \left(- 1 , 1\right)$

Then

$y - 1 = - 1 \left(x + 1\right)$

So

$y - 1 = - x - 1$

Hence $y = - x$ is the equation of the line

graph{-x [-10, 10, -5, 5]}