How do you solve using the completing the square method 3x^2 – x – 1 = 0?

1 Answer
Sep 1, 2017

Solution: x = 1/6((1+-sqrt13)

Explanation:

3x^2-x-1 =0 or 3( x^2-x/3) -1 = 0 or 3( x^2-x/3) =1

or 3( x^2-x/3 +(1/6)^2) =1+3/36 or 3(x-1/6)^2=1+1/12

or 3(x-1/6)^2=13/12 or (x-1/6)^2=13/36 or

(x-1/6)=+- sqrt(13/36) or x = 1/6 +- sqrt13/6 or

x = 1/6((1+-sqrt13)

Solution: x = 1/6((1+-sqrt13) [Ans]