16y2=81.

Solution for 16y2=81. equation:

16y^2=81.

We move all terms to the left:

16y^2-(81.)=0

We add all the numbers together, and all the variables

16y^2-81=0

a = 16; b = 0; c = -81;
Δ = b2-4ac
Δ = 02-4·16·(-81)
Δ = 5184
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5184}=72$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-72}{2*16}=\frac{-72}{32}
=-2+1/4
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+72}{2*16}=\frac{72}{32}
=2+1/4
$