(-7+5i)(-9-11i)=0

Solution for (-7+5i)(-9-11i)=0 equation:

(-7+5i)(-9-11i)=0

We add all the numbers together, and all the variables

(5i-7)(-11i-9)=0

We multiply parentheses ..

(-55i^2-45i+77i+63)=0

We get rid of parentheses

-55i^2-45i+77i+63=0

We add all the numbers together, and all the variables

-55i^2+32i+63=0

a = -55; b = 32; c = +63;
Δ = b2-4ac
Δ = 322-4·(-55)·63
Δ = 14884
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$i_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$i_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{14884}=122$
$i_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(32)-122}{2*-55}=\frac{-154}{-110}
=1+2/5
$
$i_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(32)+122}{2*-55}=\frac{90}{-110}
=-9/11
$