The elements of your multiplicative group are,
1, 2, x, x+1, x+2, 2x, 2x+1 and 2x+2. Not zero (as then your multiplicative group would not be a group...). Do you see where I got these elements from? (Strictly speaking, I should have brackets around these, like , , etc, but that doesn't really matter.)
Your identity is 1.
So, what is the order of x+1 (I presume that is the element you are trying to show is primitive)? That is, is ? ? What can you conclude?