Answer
$ a_{n}=1.5(-2)^{n-1}$ and $ a_{7}=96$
Work Step by Step
The general formula to find the nth term of a Geometric sequence is given as: $ a_{n}=a_1r^{n-1}$
$ r=\dfrac{a_2}{a_1}=\dfrac{-3}{1.5}=-2$ and $ n=7$
Now, $ a_{n}=1.5(-2)^{n-1}$
Now, $ a_{7}=1.5(-2)^{7-1}=1.5(-2)^{6}=96$
Our answers are: $ a_{n}=1.5(-2)^{n-1}$ and $ a_{7}=96$
