Answer
$-10240$
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}$
We are given that $ a_1=5, r=-2; n=12$
Now, $ a_{12}=5 \times (-2)^{12-1}=5 (-2)^{11}$
$\implies a_{12}=-10240$
