Final answer:
The commutative property of addition allows us to rearrange terms in an expression without changing their sum.
Step-by-step explanation:
The commutative property of addition states that changing the order of the numbers being added does not affect their sum. In this case, the expression is 3x+4+y. To use the commutative property of addition, we can rearrange the terms by changing the order. So, the equivalent expression would be y+3x+4.
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