Solve x^2-4x-72=0

Evaluate

x^{2} - 4 x - 72 = 0

Substitute a= 1,b= - 4 and c= - 72 into the quadratic formula x = \frac{- b \pm b ^{2} - 4 a c}{2 a}

x = \frac{4 \pm ( - 4 ) ^{2} - 4 ( - 72 )}{2}

Simplify the expression

More Steps

x = \frac{4 \pm 304}{2}

Simplify the radical expression

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x = \frac{4 \pm 4 19}{2}

Separate the equation into 2 possible cases

x = \frac{4 + 4 19}{2} x = \frac{4 - 4 19}{2}

Simplify the expression

More Steps

x = 2 + 219 x = \frac{4 - 4 19}{2}

Simplify the expression

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x = 2 + 219 x = 2 - 219

Solution

x_{1} = 2 - 219, x_{2} = 2 + 219

Alternative Form

x_{1} \approx - 6.717798, x_{2} \approx 10.717798

Solve the quadratic equation