What are the solutions to the equation x^2+2x+7=21 ?

The solutions to the equation x^2+2x+7=21 are x=-1+sqrt(15),x=-1-sqrt(15)

Find the zeros of x^2+2x+7=21

The zeros of x^2+2x+7=21 are x=-1+sqrt(15),x=-1-sqrt(15)

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x^{2} + 2 x + 7 = 21

x = - 1 + 15, x = - 1 - 15

Decimal Notation

x = 2.87298 \dots, x = - 4.87298 \dots

Solution steps

x^{2} + 2 x + 7 = 21

Move

21

to the left side

x^{2} + 2 x - 14 = 0

Solve with the quadratic formula

x_{1, 2} = \frac{- 2 \pm 2 ^{2} - 4 \cdot 1 \cdot ( - 14 )}{2 \cdot 1}

2^{2} - 4 \cdot 1 \cdot (- 14) = 215

x_{1, 2} = \frac{- 2 \pm 2 15}{2 \cdot 1}

Separate the solutions

x_{1} = \frac{- 2 + 2 15}{2 \cdot 1}, x_{2} = \frac{- 2 - 2 15}{2 \cdot 1}

x = \frac{- 2 + 2 15}{2 \cdot 1} : - 1 + 15

x = \frac{- 2 - 2 15}{2 \cdot 1} : - 1 - 15

The solutions to the quadratic equation are:

x = - 1 + 15, x = - 1 - 15

x^{2} - 20 x = - 2 x - 80

2 x (x + 3) + 2 (x + 3) = 0

12 x^{2} + 24 x - 4 = 0

9 x + 1 = 3 (x^{2} - 5) - (x - 3) (x + 2)

0 = 3 x^{2} + 8 x - 11

What are the solutions to the equation x^2+2x+7=21 ?
The solutions to the equation x^2+2x+7=21 are x=-1+sqrt(15),x=-1-sqrt(15)
Find the zeros of x^2+2x+7=21
The zeros of x^2+2x+7=21 are x=-1+sqrt(15),x=-1-sqrt(15)