4x*5x=27

Solution for 4x*5x=27 equation:

4x*5x=27

We move all terms to the left:

4x*5x-(27)=0

Wy multiply elements

20x^2-27=0

a = 20; b = 0; c = -27;
Δ = b2-4ac
Δ = 02-4·20·(-27)
Δ = 2160
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:

$\sqrt{\Delta}=\sqrt{2160}=\sqrt{144*15}=\sqrt{144}*\sqrt{15}=12\sqrt{15}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-12\sqrt{15}}{2*20}=\frac{0-12\sqrt{15}}{40}
=-\frac{12\sqrt{15}}{40}
=-\frac{3\sqrt{15}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+12\sqrt{15}}{2*20}=\frac{0+12\sqrt{15}}{40}
=\frac{12\sqrt{15}}{40}
=\frac{3\sqrt{15}}{10}
$