5x*4x=240

Solution for 5x*4x=240 equation:

5x*4x=240

We move all terms to the left:

5x*4x-(240)=0

Wy multiply elements

20x^2-240=0

a = 20; b = 0; c = -240;
Δ = b2-4ac
Δ = 02-4·20·(-240)
Δ = 19200
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:

$\sqrt{\Delta}=\sqrt{19200}=\sqrt{6400*3}=\sqrt{6400}*\sqrt{3}=80\sqrt{3}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-80\sqrt{3}}{2*20}=\frac{0-80\sqrt{3}}{40}
=-\frac{80\sqrt{3}}{40}
=-2\sqrt{3}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+80\sqrt{3}}{2*20}=\frac{0+80\sqrt{3}}{40}
=\frac{80\sqrt{3}}{40}
=2\sqrt{3}
$