3y*6y+18=90

Solution for 3y*6y+18=90 equation:

3y*6y+18=90

We move all terms to the left:

3y*6y+18-(90)=0

We add all the numbers together, and all the variables

3y*6y-72=0

Wy multiply elements

18y^2-72=0

a = 18; b = 0; c = -72;
Δ = b2-4ac
Δ = 02-4·18·(-72)
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*18}=\frac{-72}{36}
=-2
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+72}{2*18}=\frac{72}{36}
=2
$