simplify, assume all variables are positive

Answer:
9x^5y^4 (The ^ mean to the power of, so, 9x to the power of 5, then y to the power of 4. Do not put a space in between anything in this response.)
Step-by-step explanation:
Hope this helps! :D
Also, sorry to ask, but can you mark be brainliest? This took a while to solve.
Answer:
= [tex]216^{\frac{1}{3} }[/tex] × [tex]x^{\frac{9}{3} }[/tex] × [tex]y^{\frac{4}{3} }[/tex] + [tex]81^{\frac{1}{2} }[/tex] × [tex]x^{\frac{10}{2} }[/tex] × [tex]y^{\frac{8}{2} }[/tex]
= [tex]6x^{3} y^{\frac{4}{3} } + 9x^{5}y^{4}[/tex]
= [tex]6x^{3} y^{4}[/tex] × ([tex]y^{\frac{-8}{3} } + \frac{3}{2} x^{2})[/tex]