Answer
a.
$a^{6}$
b.
$a^{18}$
c.
$20x^{8}$
Work Step by Step
a.
$\frac{a^{9}a^{-2}}{a} = a^{9-2-1} = a^{6}$
b.
$(a^{2}a^{4})^{3} = (a^{2+4})^{3}= (a^{6})^{3}= (a^{6\times3})=a^{18}$
c.
$(2x)^{2}(5x^{6}) = (4x^{2})(5x^{6}) =4\times5 x^{2+6} =20x^{8}$
