X^2+y^2=105

Solution for X^2+y^2=105 equation:

X^2+X^2=105

We move all terms to the left:

X^2+X^2-(105)=0

We add all the numbers together, and all the variables

2X^2-105=0

a = 2; b = 0; c = -105;
Δ = b2-4ac
Δ = 02-4·2·(-105)
Δ = 840
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:

$\sqrt{\Delta}=\sqrt{840}=\sqrt{4*210}=\sqrt{4}*\sqrt{210}=2\sqrt{210}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{210}}{2*2}=\frac{0-2\sqrt{210}}{4}
=-\frac{2\sqrt{210}}{4}
=-\frac{\sqrt{210}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{210}}{2*2}=\frac{0+2\sqrt{210}}{4}
=\frac{2\sqrt{210}}{4}
=\frac{\sqrt{210}}{2}
$