The image shows a problem asking to combine like terms to create an equivalent expression. The expression provided is:

$y - (-3y)$

To simplify this expression:

1. Recognize that subtracting a negative number is the same as adding the positive version of that number. So,

$y - (-3y) = y + 3y$

2. Combine the like terms:

$y + 3y = 4y$

Thus, the equivalent expression is $4y$.

Would you like further details on this, or do you have any questions?

Here are 5 related questions you might explore:

1. How do you combine like terms in more complex expressions?
2. What happens when you subtract terms with different variables?
3. How do you factor expressions after combining like terms?
4. Can you solve for $y$ when given an equation involving multiple terms like this?
5. What are some common mistakes when simplifying expressions?

Tip: When simplifying expressions, always look out for negative signs and how they affect the terms being combined.