5x*4x=320

Solution for 5x*4x=320 equation:

5x*4x=320

We move all terms to the left:

5x*4x-(320)=0

Wy multiply elements

20x^2-320=0

a = 20; b = 0; c = -320;
Δ = b2-4ac
Δ = 02-4·20·(-320)
Δ = 25600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25600}=160$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-160}{2*20}=\frac{-160}{40}
=-4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+160}{2*20}=\frac{160}{40}
=4
$