Answer
$\frac{y}{9x^{7}z^{7}}$
Work Step by Step
$$(3x^{-4}yz^{-7})(3x)^{-3}$$
When a product is raised to an exponent, raise each factor to that exponent.
$$=(3x^{-4}yz^{-7})(3^{-3}x^{-3})$$
Combine like terms and simplify.
$$=(3\times3^{-3})(x^{-4}\times x^{-3})(y)(z^{-7})$$
$$=(3^{(1+(-3)})(x^{-4+(-3)})(y)(z^{-7})$$
$$=(3^{-2})(x^{-7})(y)(z^{-7})$$
When an exponent is negative, write the expression as a fraction and move the base from the numerator to the denominator (or vise versa) and make the exponent positive.
$$=\frac{y}{3^{2}x^{7}z^{7}}$$
$$=\frac{y}{9x^{7}z^{7}}$$