(2200-x^2)=(400+x^2)

Solution for (2200-x^2)=(400+x^2) equation:

(2200-x^2)=(400+x^2)

We move all terms to the left:

(2200-x^2)-((400+x^2))=0

We get rid of parentheses

-x^2-((400+x^2))+2200=0


We calculate terms in parentheses: -((400+x^2)), so:

(400+x^2)

We get rid of parentheses

x^2+400

Back to the equation:

-(x^2+400)


We add all the numbers together, and all the variables

-1x^2-(x^2+400)+2200=0

We get rid of parentheses

-1x^2-x^2-400+2200=0

We add all the numbers together, and all the variables

-2x^2+1800=0

a = -2; b = 0; c = +1800;
Δ = b2-4ac
Δ = 02-4·(-2)·1800
Δ = 14400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{14400}=120$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-120}{2*-2}=\frac{-120}{-4}
=+30
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+120}{2*-2}=\frac{120}{-4}
=-30
$