ANSWER
Option C and E
EXPLANATION
An arithmetic sequence has a constant difference among the consecutive terms.
The sequence
[tex]18,5.5,-7,-19.5,-32,...[/tex]
has a constant difference of -12.5
[tex]d = 5.5 - 18 = - 7 - 5.5 = - 19.5 - - 7 = - 32 - - 19.5 = - 12.5[/tex]
The sequence
[tex]16,32,48,64,80,...[/tex]
also has a common difference of 16
[tex]d = 32 - 16 = 48 - 32 = 64 - 48 =80 -64 = 16[/tex]
Therefore correct answers are C and E
