80=10y(3y+2)

Solution for 80=10y(3y+2) equation:

80=10y(3y+2)

We move all terms to the left:

80-(10y(3y+2))=0


We calculate terms in parentheses: -(10y(3y+2)), so:

10y(3y+2)

We multiply parentheses

30y^2+20y

Back to the equation:

-(30y^2+20y)


We get rid of parentheses

-30y^2-20y+80=0

a = -30; b = -20; c = +80;
Δ = b2-4ac
Δ = -202-4·(-30)·80
Δ = 10000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{10000}=100$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-100}{2*-30}=\frac{-80}{-60}
=1+1/3
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+100}{2*-30}=\frac{120}{-60}
=-2
$