(-8-9i)(2+4i)=0

Solution for (-8-9i)(2+4i)=0 equation:

(-8-9i)(2+4i)=0

We add all the numbers together, and all the variables

(-9i-8)(4i+2)=0

We multiply parentheses ..

(-36i^2-18i-32i-16)=0

We get rid of parentheses

-36i^2-18i-32i-16=0

We add all the numbers together, and all the variables

-36i^2-50i-16=0

a = -36; b = -50; c = -16;
Δ = b2-4ac
Δ = -502-4·(-36)·(-16)
Δ = 196
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$i_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$i_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{196}=14$
$i_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-50)-14}{2*-36}=\frac{36}{-72}
=-1/2
$
$i_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-50)+14}{2*-36}=\frac{64}{-72}
=-8/9
$