## College Algebra 7th Edition

a. $a^{6}$ b. $a^{18}$ c. $20x^{8}$
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. $(2x)^{2}(5x^{6}) = (4x^{2})(5x^{6}) =4\times5 x^{2+6} =20x^{8}$