ANSWER
[tex]3{a}^{4 } [/tex]
EXPLANATION
The cube root of
[tex]27 {a}^{12} [/tex]
is
[tex] \sqrt[3]{27 {a}^{12} } [/tex]
This is the same as:
[tex](27 {a}^{12} )^{ \frac{1}{3} } [/tex]
[tex]( {3}^{3} ({a}^{4})^{3} )^{ \frac{1}{3} } [/tex]
[tex] = (3{a}^{4} )^{3 \times \frac{1}{3} } [/tex]
[tex] = 3{a}^{4 } [/tex]
