x^2=81/400

Solution for x^2=81/400 equation:

x^2=81/400

We move all terms to the left:

x^2-(81/400)=0

We add all the numbers together, and all the variables

x^2-(+81/400)=0

We get rid of parentheses

x^2-81/400=0

We multiply all the terms by the denominator


x^2*400-81=0

Wy multiply elements

400x^2-81=0

a = 400; b = 0; c = -81;
Δ = b2-4ac
Δ = 02-4·400·(-81)
Δ = 129600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{129600}=360$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-360}{2*400}=\frac{-360}{800}
=-9/20
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+360}{2*400}=\frac{360}{800}
=9/20
$