8x*10.5x=800

Solution for 8x*10.5x=800 equation:

8x*10.5x=800

We move all terms to the left:

8x*10.5x-(800)=0

Wy multiply elements

80x^2-800=0

a = 80; b = 0; c = -800;
Δ = b2-4ac
Δ = 02-4·80·(-800)
Δ = 256000
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:

$\sqrt{\Delta}=\sqrt{256000}=\sqrt{25600*10}=\sqrt{25600}*\sqrt{10}=160\sqrt{10}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-160\sqrt{10}}{2*80}=\frac{0-160\sqrt{10}}{160}
=-\frac{160\sqrt{10}}{160}
=-\sqrt{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+160\sqrt{10}}{2*80}=\frac{0+160\sqrt{10}}{160}
=\frac{160\sqrt{10}}{160}
=\sqrt{10}
$