To write an equivalent expression, we need to simplify the given expression by combining like terms. Like terms are terms that have the same variable and exponent. We can use the distributive property to remove parentheses or other grouping signs to then combine like terms.
The given expression is -3 + 2/3y - 4 - 1/3y. We can see that there are no parentheses or grouping signs, so we can skip that step. We can also see that there are two like terms: 2/3y and -1/3y. We can combine them by adding their coefficients: 2/3 + (-1/3) = 1/3. So, we get:
-3 + 2/3y - 4 - 1/3y = -3 - 4 + (2/3 - 1/3)y = -7 + (1/3)y
This is the simplified expression that is equivalent to the given expression.