(-4x-6)(-5x-6)=0

Solution for (-4x-6)(-5x-6)=0 equation:

(-4x-6)(-5x-6)=0

We multiply parentheses ..

(+20x^2+24x+30x+36)=0

We get rid of parentheses

20x^2+24x+30x+36=0

We add all the numbers together, and all the variables

20x^2+54x+36=0

a = 20; b = 54; c = +36;
Δ = b2-4ac
Δ = 542-4·20·36
Δ = 36
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36}=6$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(54)-6}{2*20}=\frac{-60}{40}
=-1+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(54)+6}{2*20}=\frac{-48}{40}
=-1+1/5
$