36712

1. some pairs of complex numbers whose sums are real numbers are;
z_1=7+i
z_2=6-i
z_1+z_2=13
13 is a real number
2. some pairs of complex numbers whose sums are imaginary numbers are;
z_1=i+2
z_2=i-2
z_1+z_2=2i
2i is an imaginary number
3. z_1=a+ib
z_2=(-a-i)
z_1+z_2=b
b is real
z_1=a+ib
z_2=-a
z_1+z_2=ib
ib is an imaginary number
4. i*i=-1
5. i*i*i
6. a-ib=real
a+ib=imaginary