Question 607190

first, identify the first term in the sequence, call this number a.

you have {{{a=-9}}}

second, calculate the common ratio {{{r}}} of the sequence

in your case  the common ratio {{{r}}} is {{{-3}}}

if you multiply first term {{{-9}}} by  common ratio {{{-3}}} you get second term {{{27}}}

third,  you need  {{{n}}}, the term you need to find
in your case {{{n=15}}}


forth, insert these values into the equation:

{{{ar^(n-1)}}} and calculate the {{{15th}}} term

{{{-9(-3)^(15-1)=-9*(-3)^14=-9*4782969=-43046721}}}

so, your sequence is:
-9, 27 , -81, 243, -729, 2187,-6561, 19683, -59049, 177147,-531441,1594323,-4782969, 14348907, {{{-43046721}}}