The addition or subtraction of complex numbers is done by adding and subtracting only real numbers among themselves and also only imaginary numbers among themselves.
(a + bi) + (c + di) = (a + c) + (b + d)i
(a + bi) − (c + di) = (a − c) + (b − d)i
(5 + 2 i) + ( − 8 + 3 i) − (4 − 2i ) =
= (5 − 8 − 4) + (2 + 3 + 2)i = −7 + 7i
