The first one is correct. It simplifies to 5/3 x plus 2/3 x which equals 7/3 x. This becomes 2 and 1/3 x. And 8/3 is 2 and 2/3. The last 2 answers are wrong because 1/3 times -8 gives a negative number. Remember that when you multiply by 3/3 you change the form but not the number.
