Answer
$-x^{4}y$
Work Step by Step
$\sqrt[3] {-x^{12}y^{3}}$
=$(-1\times x^{12}\times y^{3})^{\frac{1}{3}}$
=$(-1)^{\frac{1}{3}}\times(x^{12})^{\frac{1}{3}}\times(y^{3})^{\frac{1}{3}}$
=$-1\times(x^{4})\times(y^{1})$
=$-x^{4}y^{1}$
=$-x^{4}y$