Final answer:
4n is not equivalent to 4n-y unless y is zero. The subtraction of y changes the value unless y equals zero.
Step-by-step explanation:
The expression 4n is not equivalent to 4n-y unless y is equal to zero. If y is any number other than zero, then the two expressions represent different values because y is being subtracted from 4n in the second expression. Without knowing the value of y, the most accurate answer to the student's question is No, the two expressions are not equivalent.