What are the solutions to the equation 4x^2-8x-21=0 ?

The solutions to the equation 4x^2-8x-21=0 are x= 7/2 ,x=-3/2

Find the zeros of 4x^2-8x-21=0

The zeros of 4x^2-8x-21=0 are x= 7/2 ,x=-3/2

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4 x^{2} - 8 x - 21 = 0

x = \frac{7}{2}, x = - \frac{3}{2}

Decimal Notation

x = 3.5, x = - 1.5

Solution steps

4 x^{2} - 8 x - 21 = 0

Solve with the quadratic formula

x_{1, 2} = \frac{- ( - 8 ) \pm ( - 8 ) ^{2} - 4 \cdot 4 ( - 21 )}{2 \cdot 4}

(- 8)^{2} - 4 \cdot 4 (- 21) = 20

x_{1, 2} = \frac{- ( - 8 ) \pm 20}{2 \cdot 4}

Separate the solutions

x_{1} = \frac{- ( - 8 ) + 20}{2 \cdot 4}, x_{2} = \frac{- ( - 8 ) - 20}{2 \cdot 4}

x = \frac{- ( - 8 ) + 20}{2 \cdot 4} : \frac{7}{2}

x = \frac{- ( - 8 ) - 20}{2 \cdot 4} : - \frac{3}{2}

The solutions to the quadratic equation are:

x = \frac{7}{2}, x = - \frac{3}{2}

\frac{4}{5 + i}

2 x^{2} - 2 x + 25 = 0

7 - (3 + 4 i) + 6 i

- 5 \cdot (- 9)

What are the solutions to the equation 4x^2-8x-21=0 ?
The solutions to the equation 4x^2-8x-21=0 are x= 7/2 ,x=-3/2
Find the zeros of 4x^2-8x-21=0
The zeros of 4x^2-8x-21=0 are x= 7/2 ,x=-3/2