To demonstrate the use of the Commutative Property in the equivalence of the expressions \(12a + 10 + a\) and \(10 + a + 12a\), here is a step-by-step outline with the missing step filled in:
Step 1: \(10 + 12a + a = 10 + a + 12a\) (Rearranging using the Commutative Property)
Step 2: \(10 + 13a = 10 + 13a\)
Step 3: The expressions are equivalent because they both equal the same value.
In Step 1, we apply the Commutative Property to rearrange the terms of \(12a + 10 + a\) so that they match the order of terms in \(10 + a + 12a\). This establishes the equivalency more clearly.