Given:
The pair of expressions in the options.
To find:
The two expressions are equivalent for any value of y.
Solution:
Two expressions are equivalent for any value of y, iff they are equivalent.
[tex]3(3y+3)=3(3y)+3(3)[/tex]
[tex]3(3y+3)=9y+9[/tex]
Clearly, [tex]3(3y+3)[/tex] is not equivalent to [tex]6y+6[/tex] or [tex]9y+6[/tex]. So, options A and B are incorrect.
[tex]9(y+3)=9(y)+9(3)[/tex]
[tex]9(y+3)=9y+27[/tex]
[tex]9(y+3)=27+9y[/tex]
The expression [tex]9(y+3)[/tex] is not equivalent to [tex]12+9y[/tex]. So, option C is incorrect.
The expression [tex]9(y+3)[/tex] is equivalent to [tex]27+9y[/tex].
Therefore, the correct option is D.