[tex]\frac{4^{12}}{4^{-9}}\\[/tex]
Given 4 = a
From the properties of exponents for the example...
[tex]\frac{a^4}{a^{-2}} = \frac{a*a*a*a}{\frac{1}{a^2} } = (a*a*a*a)*a^2 = a^4 * a^2 = a^{4+2} = a^6[/tex]
Therefore, the answer is....
[tex]4^{12}*4^{9} = 4^{12+9} = 4^{21}[/tex]
