For a x 2 + b x + c = 0 , the values of x which are the solutions to the equation are given by: x = − b ± √ b 2 − 4 a c 2 a Substituting 9 for a ; 6 for b and 1 for c gives: x = − 6 ± √ 6 2 − ( 4 ⋅ 9 ⋅ 1 ) 2 ⋅ 9 x = − 6 ± √ 36 − 36 2 ⋅ 9 x = − 6 ± √ 0 2 ⋅ 9 x = − 6 ± 0 2 ⋅ 9 x = − 6 18 x = − 1 3
