5x*4x=300

Solution for 5x*4x=300 equation:

5x*4x=300

We move all terms to the left:

5x*4x-(300)=0

Wy multiply elements

20x^2-300=0

a = 20; b = 0; c = -300;
Δ = b2-4ac
Δ = 02-4·20·(-300)
Δ = 24000
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:

$\sqrt{\Delta}=\sqrt{24000}=\sqrt{1600*15}=\sqrt{1600}*\sqrt{15}=40\sqrt{15}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-40\sqrt{15}}{2*20}=\frac{0-40\sqrt{15}}{40}
=-\frac{40\sqrt{15}}{40}
=-\sqrt{15}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+40\sqrt{15}}{2*20}=\frac{0+40\sqrt{15}}{40}
=\frac{40\sqrt{15}}{40}
=\sqrt{15}
$