x*2x=129

Solution for x*2x=129 equation:

x*2x=129

We move all terms to the left:

x*2x-(129)=0

Wy multiply elements

2x^2-129=0

a = 2; b = 0; c = -129;
Δ = b2-4ac
Δ = 02-4·2·(-129)
Δ = 1032
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:

$\sqrt{\Delta}=\sqrt{1032}=\sqrt{4*258}=\sqrt{4}*\sqrt{258}=2\sqrt{258}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{258}}{2*2}=\frac{0-2\sqrt{258}}{4}
=-\frac{2\sqrt{258}}{4}
=-\frac{\sqrt{258}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{258}}{2*2}=\frac{0+2\sqrt{258}}{4}
=\frac{2\sqrt{258}}{4}
=\frac{\sqrt{258}}{2}
$