Simplify the equation

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.

Ithink it can be put them in order by 4 possible ways.that mean 3 group of 10 rocks,or an another group of 8 rocks.