0=x2+12x-25

Solution for 0=x2+12x-25 equation:

0=x2+12x-25

We move all terms to the left:

0-(x2+12x-25)=0

We add all the numbers together, and all the variables

-(+x^2+12x-25)+0=0

We add all the numbers together, and all the variables

-(+x^2+12x-25)=0

We get rid of parentheses

-x^2-12x+25=0

We add all the numbers together, and all the variables

-1x^2-12x+25=0

a = -1; b = -12; c = +25;
Δ = b2-4ac
Δ = -122-4·(-1)·25
Δ = 244
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:

$\sqrt{\Delta}=\sqrt{244}=\sqrt{4*61}=\sqrt{4}*\sqrt{61}=2\sqrt{61}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-2\sqrt{61}}{2*-1}=\frac{12-2\sqrt{61}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+2\sqrt{61}}{2*-1}=\frac{12+2\sqrt{61}}{-2}
$