Step-by-step:
Use slope formula to find the slope. (y - y)/(x - x)
Make sure the x and y in front of the minus is a pair that goes together, as well as the x and y behind the minus sign. So
8 - -4 goes on top, that's 12
0 - -1 goes under, thats 1
12/1 is the slope which is just 12. Use either point to fill in the second x and the second y in the point-slope equation. m is the slope.
y - y = m(x - x)
y - 8 = 12(x - 0)
y - 8 = 12x
