Iterative rule for the sequence 7,21 , 63,189
It is a geometry sequence, it solution is going to be:
[tex]a_n=a_0*number^{n-1}[/tex]In this case
[tex]\begin{gathered} a_0=7\text{ } \\ number\text{ is going to be } \\ number=3 \end{gathered}[/tex]Sustituing:
[tex]a_n=7*(3)^{n-1}[/tex]This is the answer, so when n=1
[tex]\begin{gathered} a_1=7*(3)^{1-1}=7 \\ a_2=7(3)^{2-1}=7*3=21 \end{gathered}[/tex]