2x(x-8)=3

Solution for 2x(x-8)=3 equation:

2x(x-8)=3

We move all terms to the left:

2x(x-8)-(3)=0

We multiply parentheses

2x^2-16x-3=0

a = 2; b = -16; c = -3;
Δ = b2-4ac
Δ = -162-4·2·(-3)
Δ = 280
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{280}=\sqrt{4*70}=\sqrt{4}*\sqrt{70}=2\sqrt{70}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-2\sqrt{70}}{2*2}=\frac{16-2\sqrt{70}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+2\sqrt{70}}{2*2}=\frac{16+2\sqrt{70}}{4}
$