Answer :
Given
Determine if it is an arithmetic or geometric sequence:
72, 48, 24…
Solution
Arithmetic Sequence is described as a list of numbers, in which each new term differs from a preceding term by a constant quantity.
Geometric Sequence is a set of numbers wherein each element after the first is obtained by multiplying the preceding number by a constant factor.
[tex]72,48,24[/tex]-24 is the constant quantity, therefore it is an arithmetic sequence
Find the 12th term
formula
[tex]a_n=a_1+(n-1)d[/tex][tex]\begin{gathered} n=12 \\ a_1=72 \\ d=-24 \end{gathered}[/tex]We can plug in to the formula
[tex]\begin{gathered} a_{12}=72+(12-1)-24 \\ a_{12}=72+(11)-24 \\ a_{12}=72+(-264) \\ a_{12}=72-264 \\ a_{12}=-192 \end{gathered}[/tex]The 12th term of the sequence is -192