look here

A complex number a + bi where i = sqr (-1) can be represented by pair (a, b). describe a method performing only three real number multiplications to compute (e, f) representing the product of a + bi and c+di.

this is suppose to be similar to integer multiplication
damn couldnt get this one. how is this related to algorithms? eh..... can this actually be implemented? the teacher had trouble doing this on the board and we were expected to do this on the exam. faaaa... wont pass this class