No, the expressions are not equivalent.
Work Step by Step
We start by simplifying the first expression, $(2.1\times h)\times3$: The commutative property of multiplication states that changing the order of the factors does not affect the product. We use this property to rearrange the factors: $3\times(2.1\times h)$ The associative property of multiplication states that changing the grouping of the factors does not affect the product. We use this property to change the grouping of the factors: $(3\times2.1)\times h$ We now simplify by using the order of operations: We multiply inside the parentheses: $6.3\times h$ Since $6.3\times h$ shows the multiplication of two numbers, and the second expression, $6.3+h$ shows the addition of the same two numbers, the expressions are not equivalent because addition is not the same as multiplication.