(3-7i)(2-4i)=0

Solution for (3-7i)(2-4i)=0 equation:

(3-7i)(2-4i)=0

We add all the numbers together, and all the variables

(-7i+3)(-4i+2)=0

We multiply parentheses ..

(+28i^2-14i-12i+6)=0

We get rid of parentheses

28i^2-14i-12i+6=0

We add all the numbers together, and all the variables

28i^2-26i+6=0

a = 28; b = -26; c = +6;
Δ = b2-4ac
Δ = -262-4·28·6
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$i_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$i_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4}=2$
$i_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-26)-2}{2*28}=\frac{24}{56}
=3/7
$
$i_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-26)+2}{2*28}=\frac{28}{56}
=1/2
$