What are the solutions to the equation 5x(x+1)=15 ?

The solutions to the equation 5x(x+1)=15 are x=(-1+sqrt(13))/2 ,x=-(1+sqrt(13))/2

Find the zeros of 5x(x+1)=15

The zeros of 5x(x+1)=15 are x=(-1+sqrt(13))/2 ,x=-(1+sqrt(13))/2

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

5 x (x + 1) = 15

x = \frac{- 1 + 13}{2}, x = - \frac{1 + 13}{2}

Decimal Notation

x = 1.30277 \dots, x = - 2.30277 \dots

Solution steps

5 x (x + 1) = 15

Expand

5 x (x + 1) : 5 x^{2} + 5 x

5 x^{2} + 5 x = 15

Move

15

to the left side

5 x^{2} + 5 x - 15 = 0

Solve with the quadratic formula

x_{1, 2} = \frac{- 5 \pm 5 ^{2} - 4 \cdot 5 ( - 15 )}{2 \cdot 5}

5^{2} - 4 \cdot 5 (- 15) = 513

x_{1, 2} = \frac{- 5 \pm 5 13}{2 \cdot 5}

Separate the solutions

x_{1} = \frac{- 5 + 5 13}{2 \cdot 5}, x_{2} = \frac{- 5 - 5 13}{2 \cdot 5}

x = \frac{- 5 + 5 13}{2 \cdot 5} : \frac{- 1 + 13}{2}

x = \frac{- 5 - 5 13}{2 \cdot 5} : - \frac{1 + 13}{2}

The solutions to the quadratic equation are:

x = \frac{- 1 + 13}{2}, x = - \frac{1 + 13}{2}

- 3 (x - 2) - 4 x^{2} = 0

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

4 x^{2} + 4 x + 1 = 0

(2 x - 8) (2 x + 8) = 55

t^{2} + 8 t + 16 = 0

What are the solutions to the equation 5x(x+1)=15 ?
The solutions to the equation 5x(x+1)=15 are x=(-1+sqrt(13))/2 ,x=-(1+sqrt(13))/2
Find the zeros of 5x(x+1)=15
The zeros of 5x(x+1)=15 are x=(-1+sqrt(13))/2 ,x=-(1+sqrt(13))/2