1. The problem is to simplify the expression $4xaxa$. 2. We recognize that $a$ and $x$ are variables and multiplication is associative and commutative. 3. The expression $4xaxa$ can be rewritten as $4 \times x \times a \times x \times a$. 4. Grouping like terms, we get $4 \times (x \times x) \times (a \times a)$. 5. Using exponent notation, this becomes $4x^{2}a^{2}$. 6. Therefore, the simplified form of $4xaxa$ is $4x^{2}a^{2}$.