-.02d^2+1.1d+6=0

Solution for -.02d^2+1.1d+6=0 equation:

-.02d^2+1.1d+6=0

We add all the numbers together, and all the variables

-0.02d^2+1.1d+6=0

a = -0.02; b = 1.1; c = +6;
Δ = b2-4ac
Δ = 1.12-4·(-0.02)·6
Δ = 1.69
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1.1)-\sqrt{1.69}}{2*-0.02}=\frac{-1.1-\sqrt{1.69}}{-0.04}
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1.1)+\sqrt{1.69}}{2*-0.02}=\frac{-1.1+\sqrt{1.69}}{-0.04}
$