Just a moment while I review this
(9y+y) + (6+3)
The answer is 10y+9
8 = 2^3
27 = 3^3
(2^3)*(3^3)=6^3
Cube root of 6^3 = 6

and surely you know how much that is.
Rewrite the limit as

Then both numerator and denominator approach infinity (with different signs, but that's not important). Applying L'Hopital's rule, we get
