Answer
$64y^{18}z^{21}$
Work Step by Step
We are given the expression $(4y^{6}z^{7})^{3}$. We can simplify this expression using the power rule, which holds that $(a^{m})^{n}=a^{m\times n}$ (where a is a real number, and m and n are integers).
$(4y^{6}z^{7})^{3}=(4)^{3}\times(y^{6})^{3}\times(z^{7})^{3}=64y^{18}z^{21}$