Question 1045846
<pre>
3, -6 , 12, 4, 20 

Start with first term {{{highlight(3)}}}

 3 -  9 = {{{highlight(-6)}}}->second term
-6 + 18 = {{{highlight(12)}}}->third term
12 -  8 = {{{highlight( 4)}}}->fourth term
 4 + 16 = {{{highlight(20)}}}->fifth term
<font color="red">20 -  7 = 13 ->next term; so, answer is {{{13}}}
then comes
13 + 14 = {{{highlight(27)}}}
27 -  6 = {{{highlight(21)}}}</font> and so on