(6x-10)(6x+10)=90

Solution for (6x-10)(6x+10)=90 equation:

(6x-10)(6x+10)=90

We move all terms to the left:

(6x-10)(6x+10)-(90)=0

We use the square of the difference formula

36x^2-100-90=0

We add all the numbers together, and all the variables

36x^2-190=0

a = 36; b = 0; c = -190;
Δ = b2-4ac
Δ = 02-4·36·(-190)
Δ = 27360
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:

$\sqrt{\Delta}=\sqrt{27360}=\sqrt{144*190}=\sqrt{144}*\sqrt{190}=12\sqrt{190}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-12\sqrt{190}}{2*36}=\frac{0-12\sqrt{190}}{72}
=-\frac{12\sqrt{190}}{72}
=-\frac{\sqrt{190}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+12\sqrt{190}}{2*36}=\frac{0+12\sqrt{190}}{72}
=\frac{12\sqrt{190}}{72}
=\frac{\sqrt{190}}{6}
$