Simplify Each Expression $(-6)^{7} \cdot(-6)^{8} \cdot(-6)^{9}$ (B) $\left(5 x^{5} y^{3}\right)^{3}$ (C) $-6(2 y)^{0}$

Essay

Simplify each expression. Leave answers with exponents. Assume that all variables represent nonzero real numbers.
(a) $(-6)^{7} \cdot(-6)^{8} \cdot(-6)^{9}$
(b) $\left(5 x^{5} y^{3}\right)^{3}$
(c) $-6(2 y)^{0}$
(d) $\left(-\frac{4}{7}\right)^{4}$
(e) $-\left(\frac{m^{4}}{p^{6}}\right)^{4}$