1. The problem is to simplify the expression $4XaXa$. 2. We recognize that $X$ and $a$ are variables and the expression is a product of these variables with coefficients. 3. The expression can be rewritten as $4 \times X \times a \times X \times a$. 4. Group like terms: $4 \times (X \times X) \times (a \times a)$. 5. Using the rule of exponents, $X \times X = X^2$ and $a \times a = a^2$. 6. So the expression simplifies to $4X^2a^2$. 7. Therefore, the simplified form of $4XaXa$ is $4X^2a^2$.