Use the communative law of multiplication to write an equivalent expression.

x+3y

since 3y = y*3 (commutative law of multiplication)

so
x+3y = x+y*3

The commutative law of multiplication states that the order of multiplication does not affect the product. However, the expression given, x+3y, does not contain multiplication. Instead, it consists of addition.

If you meant to ask for an equivalent expression using the commutative property of addition, then it would be:

3y + x

According to the commutative property of addition, the order of the terms can be changed without affecting the result. So, x + 3y is equivalent to 3y + x.