The answer would be m = -7
You can find the slope by putting the two ordered pairs into the formula: y2-y1/x2-x1.
y2 is the second y, being 8 in your case.
x2 is the second x. Being -2 in your case.
y1 is the first y, being -6 in your case.
x1 is the first x. Being 0 in your case.
After plugging in these numbers you will get 8- -6/-2-0. This will get you 14/-2. which will equal -7, the slope.
I can explain more if you want.
Hope this helped!! :)