72y=18y^2

Solution for 72y=18y^2 equation:

72y=18y^2

We move all terms to the left:

72y-(18y^2)=0

determiningTheFunctionDomain
-18y^2+72y=0

a = -18; b = 72; c = 0;
Δ = b2-4ac
Δ = 722-4·(-18)·0
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{-(72)-72}{2*-18}=\frac{-144}{-36}
=+4
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(72)+72}{2*-18}=\frac{0}{-36}
=0
$