0=x2-18x+58

Solution for 0=x2-18x+58 equation:

0=x2-18x+58

We move all terms to the left:

0-(x2-18x+58)=0

We add all the numbers together, and all the variables

-(+x^2-18x+58)+0=0

We add all the numbers together, and all the variables

-(+x^2-18x+58)=0

We get rid of parentheses

-x^2+18x-58=0

We add all the numbers together, and all the variables

-1x^2+18x-58=0

a = -1; b = 18; c = -58;
Δ = b2-4ac
Δ = 182-4·(-1)·(-58)
Δ = 92
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:

$\sqrt{\Delta}=\sqrt{92}=\sqrt{4*23}=\sqrt{4}*\sqrt{23}=2\sqrt{23}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-2\sqrt{23}}{2*-1}=\frac{-18-2\sqrt{23}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+2\sqrt{23}}{2*-1}=\frac{-18+2\sqrt{23}}{-2}
$