81-25y^2=0

Solution for 81-25y^2=0 equation:

81-25y^2=0

a = -25; b = 0; c = +81;
Δ = b2-4ac
Δ = 02-4·(-25)·81
Δ = 8100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{8100}=90$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-90}{2*-25}=\frac{-90}{-50}
=1+4/5
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+90}{2*-25}=\frac{90}{-50}
=-1+4/5
$