(3-7i)(3-5i)=0

Solution for (3-7i)(3-5i)=0 equation:

(3-7i)(3-5i)=0

We add all the numbers together, and all the variables

(-7i+3)(-5i+3)=0

We multiply parentheses ..

(+35i^2-21i-15i+9)=0

We get rid of parentheses

35i^2-21i-15i+9=0

We add all the numbers together, and all the variables

35i^2-36i+9=0

a = 35; b = -36; c = +9;
Δ = b2-4ac
Δ = -362-4·35·9
Δ = 36
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$i_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$i_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36}=6$
$i_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-36)-6}{2*35}=\frac{30}{70}
=3/7
$
$i_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-36)+6}{2*35}=\frac{42}{70}
=3/5
$