algebra is so confusing

Question

1/8 (b - a) for a = 2 and b = 10

So is it

1/8 (b - a) =
1/8 (2 - 10)=
1/8 (-8) = -100?

Answer 1

1/8 (10-2)
= 1/8 (8)
= 8/8
=1

Answer 2

Thanks James