Answer:
r = [tex]\frac{1}{2}[/tex]
Step-by-step explanation:
The common ratio r of a geometric sequence is
r = [tex]\frac{a_{2} }{a_{1} }[/tex] = [tex]\frac{a_{3} }{a_{2} }[/tex] = [tex]\frac{a_{4} }{a_{3} }[/tex] = ......
r = [tex]\frac{-82}{-164}[/tex] = [tex]\frac{-41}{-82}[/tex] = [tex]\frac{1}{2}[/tex]
