2(y^2+5y-198)=0

Solution for 2(y^2+5y-198)=0 equation:

2(y^2+5y-198)=0

We multiply parentheses

2y^2+10y-396=0

a = 2; b = 10; c = -396;
Δ = b2-4ac
Δ = 102-4·2·(-396)
Δ = 3268
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:

$\sqrt{\Delta}=\sqrt{3268}=\sqrt{4*817}=\sqrt{4}*\sqrt{817}=2\sqrt{817}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-2\sqrt{817}}{2*2}=\frac{-10-2\sqrt{817}}{4}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+2\sqrt{817}}{2*2}=\frac{-10+2\sqrt{817}}{4}
$