about completing the square to solve f(x) = 3x^2 - 2x - 5

[georgebaseball]

Could you please correct my work? They ask me to solve this equation by completing the square:

. . .f(x) = 3x^2 - 2x - 5

This is my work

. . .3 (x^2 - (2/3)x + (1/9)) = 5

. . .3 (x - (1/3)x^2) = 5 + 1/9

Please tell me if I'm wrong. I don't know what I'm suppose to do with that 3 outside of the parenthesis

thank you

 

[galactus]

Let me introduce you to a formula which makes completing the square a piece of cake.

\(\displaystyle 3x^{2}-2x-5=0\)

a=3, b=-2, c=-5


\(\displaystyle \L\\a(x+\frac{b}{2a})^{2}+\underbrace{c-\frac{b^{2}}{4a}}_{\text{constant}}\)