Answer:
y + 4 = -(x - 8)
Explanation:
The point-slope form equation is y - y1 = m(x - x1)
Since we're given m and since they use the 4 from (8, -4) as y - (-4) = y+4, we simply need to plug in 8 into the RHS of the equation and you can check the math.
If you substitute 8 and -4 for y and x, you have:
-4 + 4 = -1(8 - 8)
0 = -1 * 0
0 = 0
You'd get -2 on both sides if you used -6 and 10, but having an equal equation means our math is true/accurate.