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] = .....
Hence
r = [tex]\frac{-52}{104}[/tex] = [tex]\frac{26}{-52}[/tex] = - [tex]\frac{1}{2}[/tex]
