(-3+5i)(18-7i)=0

Solution for (-3+5i)(18-7i)=0 equation:

(-3+5i)(18-7i)=0

We add all the numbers together, and all the variables

(5i-3)(-7i+18)=0

We multiply parentheses ..

(-35i^2+90i+21i-54)=0

We get rid of parentheses

-35i^2+90i+21i-54=0

We add all the numbers together, and all the variables

-35i^2+111i-54=0

a = -35; b = 111; c = -54;
Δ = b2-4ac
Δ = 1112-4·(-35)·(-54)
Δ = 4761
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$i_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$i_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4761}=69$
$i_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(111)-69}{2*-35}=\frac{-180}{-70}
=2+4/7
$
$i_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(111)+69}{2*-35}=\frac{-42}{-70}
=3/5
$