-25x^2+9=-520

Solution for -25x^2+9=-520 equation:

-25x^2+9=-520

We move all terms to the left:

-25x^2+9-(-520)=0

We add all the numbers together, and all the variables

-25x^2+529=0

a = -25; b = 0; c = +529;
Δ = b2-4ac
Δ = 02-4·(-25)·529
Δ = 52900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{52900}=230$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-230}{2*-25}=\frac{-230}{-50}
=4+3/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+230}{2*-25}=\frac{230}{-50}
=-4+3/5
$