Hi, the answer to this would be x6/9. I'm assuming the x4/3 and x2/3 are fractions and the x's aren't exponents. Now how I got x6/9 is shown here.
1st Step: Started off by regrouping the terms
1/3x3 x^4x^2
2nd Step: we can easily simplify 3x3 to just 9. And now we're left with 1/9x^4x^2
3rd Step: Now we can simplify the 1/9 to just x^4x^2/9
4th Step: Now we can use the product rule which is simple. So We add the exponents and simplify it to just one exponent. So x4+2=6 that simplifies to just x^6.
Final Answer: x^6/9.
Hope this helped you :)