Question 1208728
The numeric term which completes the square is  {{{(2/(3*2))^2=(1/3)^2=1/9}}}.



May go like this...
{{{x^2+2x/3+1/9-1/3-1/9=0}}}

{{{(x^2+2x/3+1/9)-3/9-1/9=0}}}

{{{(x+1/3)^2-4/9=0}}}



{{{(x+1/3)^2=4/9}}}


{{{x+1/3=0+- 2/3}}}

{{{x=-1/3+- 2/3}}}

{{{x=(-1+- 2)/3}}}


either -1   or   +1/3