(x^4 * x)^2

To simplify the expression \((x^4 * x)^2\), follow these steps:

1. Combine the powers of \(x\) inside the parentheses: \[ x^4 * x = x^{4+1} = x^5 \]

2. Now substitute this back into the expression: \[ (x^5)^2 \]

3. Apply the power of a power rule, which states that \((a^m)^n = a^{m \cdot n}\): \[ (x^5)^2 = x^{5 \cdot 2} = x^{10} \]

So, the simplified expression is: \[ \boxed{x^{10}} \]