Write with Rational (Fractional) Exponents 6x square root of x^4

$6 x \sqrt{x^{4}}$

Use $\sqrt[n]{a^{x}} = a^{\frac{x}{n}}$ to rewrite $\sqrt{x^{4}}$ as $x^{\frac{4}{2}}$ .

$6 x \cdot x^{\frac{4}{2}}$