540=3x^2+5x-8

Solution for 540=3x^2+5x-8 equation:

540=3x^2+5x-8

We move all terms to the left:

540-(3x^2+5x-8)=0

We get rid of parentheses

-3x^2-5x+8+540=0

We add all the numbers together, and all the variables

-3x^2-5x+548=0

a = -3; b = -5; c = +548;
Δ = b2-4ac
Δ = -52-4·(-3)·548
Δ = 6601
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-\sqrt{6601}}{2*-3}=\frac{5-\sqrt{6601}}{-6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+\sqrt{6601}}{2*-3}=\frac{5+\sqrt{6601}}{-6}
$