300-6q-q^2=D

Solution for 300-6q-q^2=D equation:

300-6q-q^2=

We move all terms to the left:

300-6q-q^2-()=0

We add all the numbers together, and all the variables

-1q^2-6q=0

a = -1; b = -6; c = 0;
Δ = b2-4ac
Δ = -62-4·(-1)·0
Δ = 36
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$q_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$q_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36}=6$
$q_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-6)-6}{2*-1}=\frac{0}{-2}
=0
$
$q_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+6}{2*-1}=\frac{12}{-2}
=-6
$