We'll build slope-intercept equation because you can easily see the slope and y-intercept.
To find the slope with two points: [tex]m = \frac{y_2 - y_1}{x_2 - x_1}[/tex]
[tex]\frac{-2 - 1}{1 - (-2)} = \frac{-3}{3} = -1[/tex]
Great, we have the slope, but we need y-intercept to complete the slope-intercept equation.
We already have the partially constructed slope-intercept equation: y = -1x + b
If substitute the x and y variables for an ordered pair, we can solve for b.
I use the ordered pair (1, -2)
-2 = -1(1) + b
-2 = -1 + b
-1 = b <-- Add 1 to each side
So, the slope-intercept equation is y = -1m - 1
