Answer: The resulting expression is 8+9y+4, which simplifies to 12+9y.
Step-by-step explanation: To combine like terms, we add the coefficients of the terms that are the same. In this expression, the like terms are 2y and 7y. Their coefficients are 2 and 7, respectively, so when we add them we get 2+7=9. The resulting expression is 8+9y+4, which simplifies to 12+9y.