Use the quadratic formula to find the solutions. − b ± √ b 2 − 4 ( a c ) 2 a - b ± b 2 - 4 ( a c ) 2 a Substitute the values a = 1 a = 1 , b = 0 b = 0 , and c = − 9 c = - 9 into the quadratic formula and solve for x x . 0 ± √ 0 2 − 4 ⋅ ( 1 ⋅ − 9 ) 2 ⋅ 1 0 ± 0 2 - 4 ⋅ ( 1 ⋅ - 9 ) 2 ⋅ 1 Simplify. Tap for more steps... x = ± 3 x = ± 3 The final answer is the combination of both solutions. x = 3 , − 3