-15-36d=-27d^2

Solution for -15-36d=-27d^2 equation:

-15-36d=-27d^2

We move all terms to the left:

-15-36d-(-27d^2)=0

We get rid of parentheses

27d^2-36d-15=0

a = 27; b = -36; c = -15;
Δ = b2-4ac
Δ = -362-4·27·(-15)
Δ = 2916
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2916}=54$
$d_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-36)-54}{2*27}=\frac{-18}{54}
=-1/3
$
$d_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-36)+54}{2*27}=\frac{90}{54}
=1+2/3
$