Answer:
12 - 17i
Step-by-step explanation
(2 + 3i) + (10 - 20i)
remove unnecessary parenthesis
2 + 3i + (10 - 20i)
When there is a "+" in front of an expression in parentheses, the expression remains the same.
2 + 3i + 10 - 20i
add the numbers (2 and 10) then collect like terms (3i and 20)
12 - 17i
