0.02w^2-0.3w-20=0

Solution for 0.02w^2-0.3w-20=0 equation:

0.02w^2-0.3w-20=0

a = 0.02; b = -0.3; c = -20;
Δ = b2-4ac
Δ = -0.32-4·0.02·(-20)
Δ = 1.69
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-0.3)-\sqrt{1.69}}{2*0.02}=\frac{0.3-\sqrt{1.69}}{0.04}
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.3)+\sqrt{1.69}}{2*0.02}=\frac{0.3+\sqrt{1.69}}{0.04}
$