[[x]] means that the integer should be rounded down to the greatest integer that is of the same value as x or is lower than x.
Answer:
2x^2yz + 3xy^3z - 3xyz^3
Step-by-step explanation:
First you must distribute:
xyz(2x) + xyz(3y^2) + xyz(-3z^2)
Then simplify:
2xyxx + 3xyzy^2 - 3xyz * z^2
And finally simplify each term:
2x^2yz + 3xy^3z - 3xyz^3
If you observe that 
, you can rewrite the expression as
Now, if you use the exponent rule 
, you may rewrite the expression again:
5 hours and 30 minutes or 5.5 hours
I have no idea how to help you srry . . . . .
