Given the sequences we are asked to identify whether they are geometric or arithmeti. This can be seen below.
Explanation
For an arithmetic sequence
[tex]T_2-T_1=T_3-T_2^[/tex]
For a geometric sequence
[tex]\frac{T_2}{T_1}=\frac{T_3}{T_2}[/tex]
Therefore;
Answer:
[tex]\begin{gathered} Arithmetic\text{ sequence}\Rightarrow90,87,84,81,78,.. \\ Geometric\text{ sequence}\Rightarrow4,12,36,108,324,... \\ Geometric\text{ sequence}\Rightarrow8,1,1/8,1/64,1/512,... \\ Arithmetic\text{ sequence}\Rightarrow3,10,17,24,31..... \\ Arithmetic\text{ sequence}\Rightarrow1,1.4,1.8,2.2,2.6.... \\ Geometric\text{ sequence}\Rightarrow3,1.5,0.75,0.375,... \end{gathered}[/tex]