81y*2X=72

Solution for 81y*2X=72 equation:

81y*2y=72

We move all terms to the left:

81y*2y-(72)=0

Wy multiply elements

162y^2-72=0

a = 162; b = 0; c = -72;
Δ = b2-4ac
Δ = 02-4·162·(-72)
Δ = 46656
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{46656}=216$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-216}{2*162}=\frac{-216}{324}
=-2/3
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+216}{2*162}=\frac{216}{324}
=2/3
$