2(x^2+7x-330)=0

Solution for 2(x^2+7x-330)=0 equation:

2(x^2+7x-330)=0

We multiply parentheses

2x^2+14x-660=0

a = 2; b = 14; c = -660;
Δ = b2-4ac
Δ = 142-4·2·(-660)
Δ = 5476
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5476}=74$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(14)-74}{2*2}=\frac{-88}{4}
=-22
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(14)+74}{2*2}=\frac{60}{4}
=15
$