Question 1196659
What is the missing term of the geometric sequence {-3,_,-108}?
<pre>         {{{matrix(2,3, a[2]/a[1], "=", a[3]/a[2], a[2]/(- 3), "=", (- 108)/a[2])}}} 

        {{{matrix(1,3, (a[2])^2, "=", - 3(- 108))}}} ------ Cross-multiplying  

      {{{matrix(2,3, (a[2])^2, "=", 324, sqrt((a[2])^2), "=", " "+-sqrt(324))}}}
Term 2, or {{{highlight_green(matrix(1,3, a[2], "=", " "+- 18))}}}

<font color = red><font size = 4><b>OR</font></font></b>

{{{matrix(7,3, a[n], "=", a[1]r^(n - 1), a[3], "=", - 3r^(3 - 1), - 108, "=", - 3r^2, (- 108)/(- 3), "=", r^2, 36, "=", r^2, " "+-sqrt(36), "=", sqrt(r^2), " "+- 6, "=", r)}}}      {{{highlight_green(matrix(5,3, a[n], "=", a[1]r^(n - 1), a[2], "=", - 3(highlight(6))^(2 - 1), a[2], "=", - 3(6)^1, a[2], "=", - 3(6), a[2], "=", - 18))}}}  or  {{{highlight_green(matrix(5,3, a[n], "=", a[1]r^(n - 1), a[2], "=", - 3(highlight(- 6))^(2 - 1), a[2], "=", - 3(- 6)^1, a[2], "=", - 3(- 6), a[2], "=", 18))}}}</pre>