x^2+(-5+2x)(-5+2x)=25

Solution for x^2+(-5+2x)(-5+2x)=25 equation:

x^2+(-5+2x)(-5+2x)=25

We move all terms to the left:

x^2+(-5+2x)(-5+2x)-(25)=0

We add all the numbers together, and all the variables

x^2+(2x-5)(2x-5)-25=0

We multiply parentheses ..

x^2+(+4x^2-10x-10x+25)-25=0

We get rid of parentheses

x^2+4x^2-10x-10x+25-25=0

We add all the numbers together, and all the variables

5x^2-20x=0

a = 5; b = -20; c = 0;
Δ = b2-4ac
Δ = -202-4·5·0
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-20}{2*5}=\frac{0}{10}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+20}{2*5}=\frac{40}{10}
=4
$