What are the solutions to the equation 5x^2-8x-21=0 ?

The solutions to the equation 5x^2-8x-21=0 are x=3,x=-7/5

Find the zeros of 5x^2-8x-21=0

The zeros of 5x^2-8x-21=0 are x=3,x=-7/5

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

x = 3, x = - \frac{7}{5}

Decimal Notation

x = 3, x = - 1.4

Solution steps

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

Solve with the quadratic formula

x_{1, 2} = \frac{- ( - 8 ) \pm ( - 8 ) ^{2} - 4 \cdot 5 ( - 21 )}{2 \cdot 5}

(- 8)^{2} - 4 \cdot 5 (- 21) = 22

x_{1, 2} = \frac{- ( - 8 ) \pm 22}{2 \cdot 5}

Separate the solutions

x_{1} = \frac{- ( - 8 ) + 22}{2 \cdot 5}, x_{2} = \frac{- ( - 8 ) - 22}{2 \cdot 5}

x = \frac{- ( - 8 ) + 22}{2 \cdot 5} : 3

x = \frac{- ( - 8 ) - 22}{2 \cdot 5} : - \frac{7}{5}

The solutions to the quadratic equation are:

x = 3, x = - \frac{7}{5}

\frac{3}{4} - \frac{1}{2}

\frac{1}{4} \cdot 8

\frac{1}{2} (3 x + 2) - \frac{1}{5} (x + 6) = 5

(- 2 + \frac{2 k}{n})^{2}

86 \cdot 621

What are the solutions to the equation 5x^2-8x-21=0 ?
The solutions to the equation 5x^2-8x-21=0 are x=3,x=-7/5
Find the zeros of 5x^2-8x-21=0
The zeros of 5x^2-8x-21=0 are x=3,x=-7/5