Solve -3x^2-42x-18 = 0

Evaluate

- 3 x^{2} - 42 x - 18 = 0

Multiply both sides

3 x^{2} + 42 x + 18 = 0

Substitute a= 3,b= 42 and c= 18 into the quadratic formula x = \frac{- b \pm b ^{2} - 4 a c}{2 a}

x = \frac{- 42 \pm 4 2 ^{2} - 4 \times 3 \times 18}{2 \times 3}

Simplify the expression

x = \frac{- 42 \pm 4 2 ^{2} - 4 \times 3 \times 18}{6}

Simplify the expression

More Steps

x = \frac{- 42 \pm 1548}{6}

Simplify the radical expression

More Steps

x = \frac{- 42 \pm 6 43}{6}

Separate the equation into 2 possible cases

x = \frac{- 42 + 6 43}{6} x = \frac{- 42 - 6 43}{6}

Simplify the expression

More Steps

x = - 7 + 43 x = \frac{- 42 - 6 43}{6}

Simplify the expression

More Steps

x = - 7 + 43 x = - 7 - 43

Solution

x_{1} = - 7 - 43, x_{2} = - 7 + 43

Alternative Form

x_{1} \approx - 13.557439, x_{2} \approx - 0.442561

Solve the quadratic equation