Multiplying and dividing real and complex numbers

[Einstein's Cat]

Is it possible to divide and multiply complex numbers and real numbers and if so, how does one do that? If not, why so? Cheers for your help!

 

[Samy_A]

Yes

 

[mathman]

Multiplication: $(a+ib)(c+id)=ac-bd+i(ad+bc)$
Division: $\frac{a+ib}{c+id}=\frac{(a+ib)(c-id)}{(c+id)(c-id)}=\frac{ac+bd+i(bc-ad)}{c^2+d^2}$

 

[HallsofIvy]

If you know what "complex numbers" are then you should have seen how to do arithmetic with them.