-9x^2+441=0

Solution for -9x^2+441=0 equation:

-9x^2+441=0

a = -9; b = 0; c = +441;
Δ = b2-4ac
Δ = 02-4·(-9)·441
Δ = 15876
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{15876}=126$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-126}{2*-9}=\frac{-126}{-18}
=+7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+126}{2*-9}=\frac{126}{-18}
=-7
$