What are the solutions to the equation 5r^2+15r+7=0 ?

The solutions to the equation 5r^2+15r+7=0 are r=(-15+sqrt(85))/(10),r=(-15-sqrt(85))/(10)

Find the zeros of 5r^2+15r+7=0

The zeros of 5r^2+15r+7=0 are r=(-15+sqrt(85))/(10),r=(-15-sqrt(85))/(10)

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5 r^{2} + 15 r + 7 = 0

r = \frac{- 15 + 85}{10}, r = \frac{- 15 - 85}{10}

Decimal Notation

r = - 0.57804 \dots, r = - 2.42195 \dots

Solution steps

5 r^{2} + 15 r + 7 = 0

Solve with the quadratic formula

r_{1, 2} = \frac{- 15 \pm 1 5 ^{2} - 4 \cdot 5 \cdot 7}{2 \cdot 5}

1 5^{2} - 4 \cdot 5 \cdot 7 = 85

r_{1, 2} = \frac{- 15 \pm 85}{2 \cdot 5}

Separate the solutions

r_{1} = \frac{- 15 + 85}{2 \cdot 5}, r_{2} = \frac{- 15 - 85}{2 \cdot 5}

r = \frac{- 15 + 85}{2 \cdot 5} : \frac{- 15 + 85}{10}

r = \frac{- 15 - 85}{2 \cdot 5} : \frac{- 15 - 85}{10}

The solutions to the quadratic equation are:

r = \frac{- 15 + 85}{10}, r = \frac{- 15 - 85}{10}

20 x^{2} - 20 x = 40

- x^{2} = - 15 - 2 x

9 x^{2} - 225 = 0

(9 x - 14) (8 x + 15) = 7 + 13 x

5 x^{2} + x - \frac{1}{20} = 0

What are the solutions to the equation 5r^2+15r+7=0 ?
The solutions to the equation 5r^2+15r+7=0 are r=(-15+sqrt(85))/(10),r=(-15-sqrt(85))/(10)
Find the zeros of 5r^2+15r+7=0
The zeros of 5r^2+15r+7=0 are r=(-15+sqrt(85))/(10),r=(-15-sqrt(85))/(10)