What are the solutions to the equation x(x-10)=21 ?

The solutions to the equation x(x-10)=21 are x=5+sqrt(46),x=5-sqrt(46)

Find the zeros of x(x-10)=21

The zeros of x(x-10)=21 are x=5+sqrt(46),x=5-sqrt(46)

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x (x - 10) = 21

x = 5 + 46, x = 5 - 46

Decimal Notation

x = 11.78232 \dots, x = - 1.78232 \dots

Solution steps

x (x - 10) = 21

Expand

x (x - 10) : x^{2} - 10 x

x^{2} - 10 x = 21

Move

21

to the left side

x^{2} - 10 x - 21 = 0

Solve with the quadratic formula

x_{1, 2} = \frac{- ( - 10 ) \pm ( - 10 ) ^{2} - 4 \cdot 1 \cdot ( - 21 )}{2 \cdot 1}

(- 10)^{2} - 4 \cdot 1 \cdot (- 21) = 246

x_{1, 2} = \frac{- ( - 10 ) \pm 2 46}{2 \cdot 1}

Separate the solutions

x_{1} = \frac{- ( - 10 ) + 2 46}{2 \cdot 1}, x_{2} = \frac{- ( - 10 ) - 2 46}{2 \cdot 1}

x = \frac{- ( - 10 ) + 2 46}{2 \cdot 1} : 5 + 46

x = \frac{- ( - 10 ) - 2 46}{2 \cdot 1} : 5 - 46

The solutions to the quadratic equation are:

x = 5 + 46, x = 5 - 46

x^{2} + 2 = 11

2 x^{2} + 65 x - 200 = 0

3 x^{2} + 7 x - 28 = 0

x^{2} + 9 = 9

- 4 x^{2} + 5 x = 6

What are the solutions to the equation x(x-10)=21 ?
The solutions to the equation x(x-10)=21 are x=5+sqrt(46),x=5-sqrt(46)
Find the zeros of x(x-10)=21
The zeros of x(x-10)=21 are x=5+sqrt(46),x=5-sqrt(46)