First we find the slope.
Slope or m = [tex] \frac{Y2 - Y1}{X2 - X1} [/tex]
where X1 is the x-coordinate of the first ordered pair and Y1 is the y-coordinate of the first ordered pair. Same applies to X2 and Y2 for the second ordered pair.
m = [tex] \frac{- 4 - (-1)}{1 - (- 2)} [/tex]
m = [tex] \frac{- 4 + 1}{1 + 2} [/tex]
m = [tex] \frac{- 3}{3} [/tex]
m = - 1
Your equation starts as y = - 1x + b or just y = - x + b
Now we plug either ordered pair into the equation and solve for b to get our complete linear function.
- 4 = - (1) + b
- 4 = - 1 + b
- 4 + 1 = b
- 3 = b
Your equation is:
y = - x - 3
