[tex]a_1=2;\ r=-\dfrac{3}{2}\\\\a_2=a_1r\to a_2=2\cdot\left(-\dfrac{3}{2}\right)=-3\\\\a_3=a_2r\to a_3=-3\cdot\left(-\dfrac{3}{2}\right)=\dfrac{9}{2}\\\\a_4=a_3r\to a_4=\dfrac{9}{2}\cdot\left(-\dfrac{3}{2}\right)=-\dfrac{27}{4}\\\\a_5=a_4r\to a_5=-\dfrac{27}{4}\cdot\left(-\dfrac{3}{2}\right)=\dfrac{81}{8}[/tex]