6x^{2 }– x – 2 = 0; x = 2/3, - 1
Now put x = - 1 in L.H.S. of equation.
L.H.S. = 6 × (- 1)2 – ( - 1) – 2
= 6 + 1 – 2
= 7 – 2 = 5 ≠ 0 ≠ R.H.S.
Hence, x = -1 is not a root of the equation.
Put x = 2/3 in L.H.S. of equation.
L.H.S. = 6 × (2/3)^{2} – 2/3 – 2
= 24/9 – 2/3 – 2
= 8/3 – 2/3 – 2 = 0
= 8 – 8 = 0
= R.H.S.
Hence, x = 2/3 is a solution of given equation.