What are the solutions to the equation x^2-x-21=0 ?

The solutions to the equation x^2-x-21=0 are x=(1+sqrt(85))/2 ,x=(1-sqrt(85))/2

Find the zeros of x^2-x-21=0

The zeros of x^2-x-21=0 are x=(1+sqrt(85))/2 ,x=(1-sqrt(85))/2

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x^{2} - x - 21 = 0

x = \frac{1 + 85}{2}, x = \frac{1 - 85}{2}

Decimal

x = 5.10977 \dots, x = - 4.10977 \dots

Solution steps

x^{2} - x - 21 = 0

Solve with the quadratic formula

x_{1, 2} = \frac{- ( - 1 ) \pm ( - 1 ) ^{2} - 4 \cdot 1 \cdot ( - 21 )}{2 \cdot 1}

(- 1)^{2} - 4 \cdot 1 \cdot (- 21) = 85

x_{1, 2} = \frac{- ( - 1 ) \pm 85}{2 \cdot 1}

Separate the solutions

x_{1} = \frac{- ( - 1 ) + 85}{2 \cdot 1}, x_{2} = \frac{- ( - 1 ) - 85}{2 \cdot 1}

x = \frac{- ( - 1 ) + 85}{2 \cdot 1} : \frac{1 + 85}{2}

x = \frac{- ( - 1 ) - 85}{2 \cdot 1} : \frac{1 - 85}{2}

The solutions to the quadratic equation are:

x = \frac{1 + 85}{2}, x = \frac{1 - 85}{2}

x, 16 x^{2} + 25 y^{2} + 400 = 0

x, (f \circ g) f = x^{2}

x^{2} + 1 = 6 x

x^{2} + 1 = 50

- 5 (x - 8) (x + 4) = 0

What are the solutions to the equation x^2-x-21=0 ?
The solutions to the equation x^2-x-21=0 are x=(1+sqrt(85))/2 ,x=(1-sqrt(85))/2
Find the zeros of x^2-x-21=0
The zeros of x^2-x-21=0 are x=(1+sqrt(85))/2 ,x=(1-sqrt(85))/2