Solve x^(2)-4x-9=0

Evaluate

x^{2} - 4 x - 9 = 0

Substitute a= 1,b= - 4 and c= - 9 into the quadratic formula x = \frac{- b \pm b ^{2} - 4 a c}{2 a}

x = \frac{4 \pm ( - 4 ) ^{2} - 4 ( - 9 )}{2}

Simplify the expression

More Steps

x = \frac{4 \pm 52}{2}

Simplify the radical expression

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x = \frac{4 \pm 2 13}{2}

Separate the equation into 2 possible cases

x = \frac{4 + 2 13}{2} x = \frac{4 - 2 13}{2}

Simplify the expression

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x = 2 + 13 x = \frac{4 - 2 13}{2}

Simplify the expression

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x = 2 + 13 x = 2 - 13

Solution

x_{1} = 2 - 13, x_{2} = 2 + 13

Alternative Form

x_{1} \approx - 1.605551, x_{2} \approx 5.605551

Solve the quadratic equation