y – y1 = m(x – x1)
First, you have to find m, or the slope.
This is
y - y
-------
x - x
It doesn't matter which way you put it in, but I'm going to do it like this:
-10 - (-8)
-------------
-7 - (-6)
This reduces into:
-2/-1 = 2
Now, it'll look like this (according to your answer choices, but you can use the other coordinate, also):
y - (-10) = 2(x - (-7))
This turns into:
y + 10 = 2(x + 7)
This answer is: C.