(10+9i)⋅ ¯¯¯¯¯¯
(10+9i)
Perform the indicated operation & simplify. Express the answer in terms of i (as a complex number). The second (10+9i) is supposed to be under the bar.
multiply by conjugate top and bottom, giving
(10+9i)(10+19i)
--------------------- = (19+180i)/181
(10-9i)(10+9i)