Respuesta :

iGreen
We multiply the exponents outside of the parenthesis to all the exponents inside the parenthesis.

[tex]\sf(y^3)^3\rightarrow~y^{3\times3}\rightarrow~\boxed{\sf~y^9}[/tex]
TSO
We will use this property in exponents to answer your question:

[tex]\sf{(a^b)^c=a^{b\times c}}[/tex]

So basically we multiply the exponents when it is outside of the parenthesis. So:

[tex]\sf{(y^3)^3=y^{3\times3}}[/tex]

[tex]\sf{=y^9}[/tex]

So your answer would be [tex]\boxed{\sf{y^9}}[/tex]