## Calculus with Applications (10th Edition)

$27^{2/3}\cdot 27^{-1/3}=$ ...use: $a^{m}\cdot a^{n}=a^{m+n}$ $=27^{(2/3)+(-1/3)}$ $=27^{2/3-1/3}$ $=27^{1/3}=$ ... recognize: $27=3^{3}$ $=(3^{3})^{1/3}=$ ...use: $(a^{m})^{n}=a^{mn}$ $=3^{1}=3$