Which expressions are equivalent to 6 +(–x) + 2x + (–7) + 2x? Check all that apply.
x + x + 6 – 7 + x
2x + 2 + x
3 – x + 2x – 4 + 2x
x – 1
x + 1 ?



Please help, the only answer I've seen is A, but it's multiple choice.