# How do you graph using slope and intercept of x+y=-1 ?

Dec 21, 2015

$m = - 1$
$b = - 1$

#### Explanation:

Convert $x + y = - 1$ to slope-intercept form by solving for $y$.

Subtract $x$ from both sides.

$y = - x - 1$

The equation is now in slope-intercept form, $y = m x + b$, where $m$ is the slope, and $b$ is the y-intercept.

$m = - 1$ and $b = - 1$

Since any whole number can be expressed as a fraction with $1$ as the denominator, we can express $m$ as $\frac{- 1}{1}$. Since $b$ is the value of $y$ when $x = 0$, we have the point $\left(0 , - 1\right)$.

Plot the point, then use the slope to find more points. Starting at $\left(0 , - 1\right)$, move down one space and right one space. Plot the point. You only need two points for a straight line, but you can plot more if you wish. Draw a straight line through the points.

graph{y=-x-1 [-12.6, 12.6, -6.3, 6.3]}