-9x^2+25=0

Solution for -9x^2+25=0 equation:

-9x^2+25=0

a = -9; b = 0; c = +25;
Δ = b2-4ac
Δ = 02-4·(-9)·25
Δ = 900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{900}=30$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-30}{2*-9}=\frac{-30}{-18}
=1+2/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+30}{2*-9}=\frac{30}{-18}
=-1+2/3
$