(2x)^2-x^2=3.25^2

Solution for (2x)^2-x^2=3.25^2 equation:

(2x)^2-x^2=3.25^2

We move all terms to the left:

(2x)^2-x^2-(3.25^2)=0

We add all the numbers together, and all the variables

x^2-10.5625=0

a = 1; b = 0; c = -10.5625;
Δ = b2-4ac
Δ = 02-4·1·(-10.5625)
Δ = 42.25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-\sqrt{42.25}}{2*1}=\frac{0-\sqrt{42.25}}{2}
=-\frac{\sqrt{}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{42.25}}{2*1}=\frac{0+\sqrt{42.25}}{2}
=\frac{\sqrt{}}{2}
$