Math Snap

STEP 1

What is this asking?
Find the slope of the line that goes through the points $(-9, 9)$ and $(1, -1)$.
Watch out!
Don't mix up the x and y coordinates!
Also, remember that slope is rise over run, not run over rise.

STEP 2

1. Find the rise.
2. Find the run.
3. Calculate the slope.

STEP 3

The rise is the change in the y-values.
We go from $y_1 = 9$ to $y_2 = -1$.

STEP 4

Let's calculate the change: $y_2 - y_1 = -1 - 9 = \mathbf{-10}$.
So, our rise is $\mathbf{-10}$.
This means we are going down $\mathbf{10}$ units!

STEP 5

The run is the change in the x-values.
We go from $x_1 = -9$ to $x_2 = 1$.

STEP 6

Let's calculate the change: $x_2 - x_1 = 1 - (-9) = 1 + 9 = \mathbf{10}$.
Our run is $\mathbf{10}$, meaning we move $\mathbf{10}$ units to the right!

STEP 7

Remember, slope is rise over run.

STEP 8

We found that the rise is $-10$ and the run is $10$.

STEP 9

So, the slope is: $$\frac{\text{rise}}{\text{run}} = \frac{-10}{10} = \frac{-1 \cdot 10}{1 \cdot 10} = \frac{-1}{1} = \mathbf{-1}$$

The slope of the line is $\mathbf{-1}$.