64=(2x+8)x

Solution for 64=(2x+8)x equation:

64=(2x+8)x

We move all terms to the left:

64-((2x+8)x)=0


We calculate terms in parentheses: -((2x+8)x), so:

(2x+8)x

We multiply parentheses

2x^2+8x

Back to the equation:

-(2x^2+8x)


We get rid of parentheses

-2x^2-8x+64=0

a = -2; b = -8; c = +64;
Δ = b2-4ac
Δ = -82-4·(-2)·64
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-24}{2*-2}=\frac{-16}{-4}
=+4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+24}{2*-2}=\frac{32}{-4}
=-8
$