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

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

Find the zeros of 4x^2+8x=21

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

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4 x^{2} + 8 x = 21

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

Decimal Notation

x = 1.5, x = - 3.5

Solution steps

4 x^{2} + 8 x = 21

Move

21

to the left side

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{3}{2}

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

The solutions to the quadratic equation are:

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

1 3^{3}

6 (- \frac{1}{3})

x^{2} - y^{2} + 2 x - 2 y

(2 - 1)^{2}

4 x^{3} - 4

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