First, you will need to subtract your Y1 for your Y2. In this case your Y2 will be -4 and your Y1 is also -4. -4 minus -4 equals 0. This will be your numerator of your fraction to divide at the end. Now you need to subtract your X1 from your X2. Your X2 will be 2 and your X1 will be 8. 2 minus 8 equals -6. This will be your denominator. Finally, you will divide 0 by -6. This equals 0. Therefore, your slope is 0.