Answer
$\dfrac {244}{27}$
Work Step by Step
$r=\dfrac {\dfrac {-4}{9}}{\dfrac {4}{3}}=\dfrac {\dfrac {4}{3}}{-4}=\dfrac {-a}{12}=-\dfrac {1}{3};a_{1}=12\Rightarrow S_{n}=\dfrac {a_{1}\left( r^{n}-1\right) }{r-1}=\dfrac {12\times \left( \left( -\dfrac {1}{3}\right) ^{5}-1\right) }{\left( -\dfrac {1}{3}-1\right) }=\dfrac {12\times \left( \dfrac {-244}{243}\right) }{\dfrac {-4}{3}}=\dfrac {244}{27}$
