5x*4x=500

Solution for 5x*4x=500 equation:

5x*4x=500

We move all terms to the left:

5x*4x-(500)=0

Wy multiply elements

20x^2-500=0

a = 20; b = 0; c = -500;
Δ = b2-4ac
Δ = 02-4·20·(-500)
Δ = 40000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{40000}=200$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-200}{2*20}=\frac{-200}{40}
=-5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+200}{2*20}=\frac{200}{40}
=5
$