5x*10.5x=3.28

Solution for 5x*10.5x=3.28 equation:

5x*10.5x=3.28

We move all terms to the left:

5x*10.5x-(3.28)=0

We add all the numbers together, and all the variables

5x*10.5x-3.28=0

Wy multiply elements

50x^2-3.28=0

a = 50; b = 0; c = -3.28;
Δ = b2-4ac
Δ = 02-4·50·(-3.28)
Δ = 656
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:

$\sqrt{\Delta}=\sqrt{656}=\sqrt{16*41}=\sqrt{16}*\sqrt{41}=4\sqrt{41}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4\sqrt{41}}{2*50}=\frac{0-4\sqrt{41}}{100}
=-\frac{4\sqrt{41}}{100}
=-\frac{\sqrt{41}}{25}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4\sqrt{41}}{2*50}=\frac{0+4\sqrt{41}}{100}
=\frac{4\sqrt{41}}{100}
=\frac{\sqrt{41}}{25}
$