625=(x^2)+(x^2)-6x+9

Solution for 625=(x^2)+(x^2)-6x+9 equation:

625=(x^2)+(x^2)-6x+9

We move all terms to the left:

625-((x^2)+(x^2)-6x+9)=0

We get rid of parentheses

-x^2-x^2+6x-9+625=0

We add all the numbers together, and all the variables

-2x^2+6x+616=0

a = -2; b = 6; c = +616;
Δ = b2-4ac
Δ = 62-4·(-2)·616
Δ = 4964
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:

$\sqrt{\Delta}=\sqrt{4964}=\sqrt{4*1241}=\sqrt{4}*\sqrt{1241}=2\sqrt{1241}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-2\sqrt{1241}}{2*-2}=\frac{-6-2\sqrt{1241}}{-4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+2\sqrt{1241}}{2*-2}=\frac{-6+2\sqrt{1241}}{-4}
$