2x*4.25x=65

Solution for 2x*4.25x=65 equation:

2x*4.25x=65

We move all terms to the left:

2x*4.25x-(65)=0

Wy multiply elements

8x^2-65=0

a = 8; b = 0; c = -65;
Δ = b2-4ac
Δ = 02-4·8·(-65)
Δ = 2080
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:

$\sqrt{\Delta}=\sqrt{2080}=\sqrt{16*130}=\sqrt{16}*\sqrt{130}=4\sqrt{130}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4\sqrt{130}}{2*8}=\frac{0-4\sqrt{130}}{16}
=-\frac{4\sqrt{130}}{16}
=-\frac{\sqrt{130}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4\sqrt{130}}{2*8}=\frac{0+4\sqrt{130}}{16}
=\frac{4\sqrt{130}}{16}
=\frac{\sqrt{130}}{4}
$