Answer:
If Z is a complex number:
Z = a + b*i
where a and b are real numbers, and i is an imaginary number.
Then "a" is the real part.
"b*i" is the imaginary part.
The conjugate of Z is:
Zc = a - b*i
So the sign of the imaginary part changes.
Then:
Sum:
Z + Zc = (a + bi) + (a - bi) = 2*a + 0 = 2*a
and remember that a is a real number, then 2*a is also a real numer.
The correct answer is "A real number".
Difference:
Z - Zc = (a + bi) - (a - bi) = 2b*i
and this is a pure imaginary number, so here the correct answer is: "a pure imaginary number"
