9
I can see why people get 1, but outside the order of operations, we work left to right.
6 / 2 x (2+1) = 6 / 2 x 3 = 3 x 3 = 9
Not: 6 / 2 x (2+1) = 6 / 2 x 3 = 6 / 6 = 1