Answer:
1. 19
2. 9 + 11i
Explanation:
first problem:
first, we rewrite it and remove the parentheses.
12 - 3i + 7 + 3i
then, just remove the opposites and calculate.
19
second problem:
again, we rewrite and remove the parentheses.
12 + 4i - 3 + 7i
then, we calculate and collect like terms.
9 + 11i