To simplify the expression $-3(y + 3) + 4y$, let's proceed with the following steps:

Step-by-Step Solution

1. Distribute $-3$ to both terms inside the parentheses: $-3 \cdot y = -3y$ $-3 \cdot 3 = -9$ So, the expression becomes: $-3y - 9 + 4y$

2. Combine like terms ($-3y$ and $4y$): $(-3y + 4y) - 9 = y - 9$

Final Answer

The simplified form of the expression is: $y - 9$

Would you like further details or have any questions?

Here are some related questions to consider:

1. What happens if you change the constant term inside the parentheses?
2. How would the solution differ if the expression were $-3(y + 3) - 4y$ instead?
3. Can you expand $-5(y + 2) + 7y$ similarly?
4. How does the distributive property work for expressions with more than one variable?
5. What is the result of factoring $-3y - 9 + 4y$ back to its original form?

Tip: When simplifying expressions, always look for terms you can combine after distribution!