0=6y+y^2-105

Solution for 0=6y+y^2-105 equation:

0=6y+y^2-105

We move all terms to the left:

0-(6y+y^2-105)=0

We add all the numbers together, and all the variables

-(6y+y^2-105)=0

We get rid of parentheses

-y^2-6y+105=0

We add all the numbers together, and all the variables

-1y^2-6y+105=0

a = -1; b = -6; c = +105;
Δ = b2-4ac
Δ = -62-4·(-1)·105
Δ = 456
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{456}=\sqrt{4*114}=\sqrt{4}*\sqrt{114}=2\sqrt{114}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-6)-2\sqrt{114}}{2*-1}=\frac{6-2\sqrt{114}}{-2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+2\sqrt{114}}{2*-1}=\frac{6+2\sqrt{114}}{-2}
$