`9v^2-6v-2=0`

Rearrange:

`9v^2-6v=2`

Divide throughout by 9:

`v^2-2/3v=2/9`

Write as a perfect square:

`v^2-2/3v+(1/3)^2=2/9+(1/3)^2`

`(v-1/3)^2=2/9+1/9=1/3`

Solve:

`v-1/3 = +-sqrt(1/3)`

`v=1/3+-sqrt(1/3)`

`v=-0.244\ "or"\ v=0.911`