The rule for expressing a radical as a rational exponent is as follows: [tex] \sqrt[n]{x^y} = x^ \frac{y}{n} [/tex] So, to find [tex] \sqrt[3]{27x^2y^3z^4} [/tex] use that rule. The cube root of 27 is 3, so the equation will start with 3. [tex]3x^ \frac{2}{3} yz^ \frac{4}{3} [/tex] Hope that helps!