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2(x+4)(x+2)=x^2+2x

2(x+4)(x+2)=x^2+2x equation

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Numerical solution:

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The solution

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                     2      
2*(x + 4)*(x + 2) = x  + 2*x
$$\left(x + 2\right) 2 \left(x + 4\right) = x^{2} + 2 x$$
Detail solution
Move right part of the equation to
left part with negative sign.

The equation is transformed from
$$\left(x + 2\right) 2 \left(x + 4\right) = x^{2} + 2 x$$
to
$$\left(x + 2\right) 2 \left(x + 4\right) + \left(- x^{2} - 2 x\right) = 0$$
Expand the expression in the equation
$$\left(x + 2\right) 2 \left(x + 4\right) + \left(- x^{2} - 2 x\right) = 0$$
We get the quadratic equation
$$x^{2} + 10 x + 16 = 0$$
This equation is of the form
a*x^2 + b*x + c = 0

A quadratic equation can be solved
using the discriminant.
The roots of the quadratic equation:
$$x_{1} = \frac{\sqrt{D} - b}{2 a}$$
$$x_{2} = \frac{- \sqrt{D} - b}{2 a}$$
where D = b^2 - 4*a*c - it is the discriminant.
Because
$$a = 1$$
$$b = 10$$
$$c = 16$$
, then
D = b^2 - 4 * a * c = 

(10)^2 - 4 * (1) * (16) = 36

Because D > 0, then the equation has two roots.
x1 = (-b + sqrt(D)) / (2*a)

x2 = (-b - sqrt(D)) / (2*a)

or
$$x_{1} = -2$$
$$x_{2} = -8$$
The graph
Rapid solution [src]
x1 = -8
$$x_{1} = -8$$
x2 = -2
$$x_{2} = -2$$
x2 = -2
Sum and product of roots [src]
sum
-8 - 2
$$-8 - 2$$
=
-10
$$-10$$
product
-8*(-2)
$$- -16$$
=
16
$$16$$
16
Numerical answer [src]
x1 = -2.0
x2 = -8.0
x2 = -8.0
The graph
2(x+4)(x+2)=x^2+2x equation