performs the mentioned operation and write the answers in standard form.
( -4 + 7i ) + (5 -10i )
Actually there isn't much to do here other than add or subtract. Notice that the parentheses on the first terms are just there to mention which we're thinking of that term as a complex number and generally aren't used.
( -4 + 7i ) + (5 -10i ) + 1 - 3i