Given that S6 is 133 and the common ratio (r) is -2/3.
We know that the sum of n terms of a gp whose common ratio is less than 1 is
[tex]S_n=\frac{a(1-r^n)}{(1-r)}[/tex]So,
[tex]\begin{gathered} 133=\frac{a(1-(-\frac{2}{3})^6)}{1-(-\frac{2}{3})} \\ 133=\frac{a(1-\frac{64}{729})}{1+\frac{2}{3}} \\ 133=\frac{a(\frac{665}{729})}{\frac{5}{3}} \\ 133=\frac{a(133)}{243} \\ a=243 \end{gathered}[/tex]Now, we have known that the first term of the gp is 243.
So, the second term is:
[tex]ar=243\times(-\frac{2}{3})=-162[/tex]The third term is:
[tex]ar^2=243\times(-\frac{2}{3})^2=108[/tex]Thus, the first three terms are 243, -162, 108.