x*x-1=756

Solution for x*x-1=756 equation:

x*x-1=756

We move all terms to the left:

x*x-1-(756)=0

We add all the numbers together, and all the variables

x*x-757=0

Wy multiply elements

x^2-757=0

a = 1; b = 0; c = -757;
Δ = b2-4ac
Δ = 02-4·1·(-757)
Δ = 3028
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:

$\sqrt{\Delta}=\sqrt{3028}=\sqrt{4*757}=\sqrt{4}*\sqrt{757}=2\sqrt{757}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{757}}{2*1}=\frac{0-2\sqrt{757}}{2}
=-\frac{2\sqrt{757}}{2}
=-\sqrt{757}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{757}}{2*1}=\frac{0+2\sqrt{757}}{2}
=\frac{2\sqrt{757}}{2}
=\sqrt{757}
$