Question

Find the imaginary part of (5 - 12i)²​

Answer 1

(5-12i)^2
Write it twice:
(5-12i)(5-12i)
Distribute:
25-60i-60i+144i^2
Combine like terms:
25-120i+144i^2
Change i^2 to -1, remember the values of i:
25-120i-144
Combine like terms:
-199-120i