The problem asks to simplify the expression $a + a$.

1. Problem Description

The problem asks to simplify the expression $a + a$.

2. Solution Steps

We are given the expression $a + a$.

This expression represents the sum of two identical terms, both equal to $a$.

We can rewrite this as $1a + 1a$.

Combining like terms, we have $(1+1)a$.

Since $1 + 1 = 2$, we have $2a$.

3. Final Answer

$2a$