Answer:
[tex]x = 9 + 11i[/tex]
Step-by-step explanation:
let's make the other number x and add it with -4-5i, equate to 5+6i
[tex] - 4 - 5i + x = 5 + 6i[/tex]
add 4 and 5i to both sides to get x on its own:
[tex]x = 5 + 6i + 4 + 5i[/tex]
collect like terms. This is the other number.
[tex]x = 9 + 11i[/tex]
