(X+1)2-4x2=0

Solution for (X+1)2-4x2=0 equation:

(X+1)2-4X^2=0

We multiply parentheses

-4X^2+2X+2=0

a = -4; b = 2; c = +2;
Δ = b2-4ac
Δ = 22-4·(-4)·2
Δ = 36
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36}=6$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-6}{2*-4}=\frac{-8}{-8}
=1
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+6}{2*-4}=\frac{4}{-8}
=-1/2
$