No, the work shown above is not correct. The mistake happened in step #2.
Question:
(11+2i)-(3-10i)
Distribute the negative:
(11+2i)-3+10i
Bring it down:
11+2i-3+10i
Add like terms:
2i+10i=12i
11-3=8
Combine:
12i+8
^This is the correct answer
————-
If you are trying to find the value of the variable i then:
Problem:
12i+8
Bring to the other side:
12i=-8
Isolate the variable:
i=-8/12
Simplify:
i=-2/3