20=5x2+18/6

Solution for 20=5x2+18/6 equation:

20=5x^2+18/6

We move all terms to the left:

20-(5x^2+18/6)=0

We get rid of parentheses

-5x^2+20-18/6=0

We multiply all the terms by the denominator


-5x^2*6-18+20*6=0

We add all the numbers together, and all the variables

-5x^2*6+102=0

Wy multiply elements

-30x^2+102=0

a = -30; b = 0; c = +102;
Δ = b2-4ac
Δ = 02-4·(-30)·102
Δ = 12240
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:

$\sqrt{\Delta}=\sqrt{12240}=\sqrt{144*85}=\sqrt{144}*\sqrt{85}=12\sqrt{85}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-12\sqrt{85}}{2*-30}=\frac{0-12\sqrt{85}}{-60}
=-\frac{12\sqrt{85}}{-60}
=-\frac{\sqrt{85}}{-5}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+12\sqrt{85}}{2*-30}=\frac{0+12\sqrt{85}}{-60}
=\frac{12\sqrt{85}}{-60}
=\frac{\sqrt{85}}{-5}
$