(1+x)*(1+x)=650

Solution for (1+x)*(1+x)=650 equation:

(1+x)(1+x)=650

We move all terms to the left:

(1+x)(1+x)-(650)=0

We add all the numbers together, and all the variables

(x+1)(x+1)-650=0

We multiply parentheses ..

(+x^2+x+x+1)-650=0

We get rid of parentheses

x^2+x+x+1-650=0

We add all the numbers together, and all the variables

x^2+2x-649=0

a = 1; b = 2; c = -649;
Δ = b2-4ac
Δ = 22-4·1·(-649)
Δ = 2600
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:

$\sqrt{\Delta}=\sqrt{2600}=\sqrt{100*26}=\sqrt{100}*\sqrt{26}=10\sqrt{26}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-10\sqrt{26}}{2*1}=\frac{-2-10\sqrt{26}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+10\sqrt{26}}{2*1}=\frac{-2+10\sqrt{26}}{2}
$