2w^2+18w-90=0

Solution for 2w^2+18w-90=0 equation:

2w^2+18w-90=0

a = 2; b = 18; c = -90;
Δ = b2-4ac
Δ = 182-4·2·(-90)
Δ = 1044
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1044}=\sqrt{36*29}=\sqrt{36}*\sqrt{29}=6\sqrt{29}$
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-6\sqrt{29}}{2*2}=\frac{-18-6\sqrt{29}}{4}
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+6\sqrt{29}}{2*2}=\frac{-18+6\sqrt{29}}{4}
$