Complex numbers

[Guest]

Are these correct?

1.(2+i)/(3-2i)
(2+i)/(3-2i) * 3+2i/3+2i
(2+i)(3+2i)/(3-2i)(3+2i)
6+4i+3i+i^2/9+6i-6i-4i^2
5+7i/13 = 5/13 + 7/13 i

2. (3-i)/(1+2i)
(3-i)/(1+2i) * 1-2i/1-2i
(3-i)(1-2i)/(1+2i)(1-2i)
3-6i-1i+2i^2/1-2i+2i-4i^2
3-7i+2(-1)/1-4(-1)
1-7i/5 = 1/5 - 7/5 i

 

[tkhunny]

1) Close i * 2* = -2 ≠ -1
Also, there is a bit of a notation breakdown. Steps 2 and 4 are very much unclear. Add parentheses to clarify intent.

Yes: (3+2i)/(3+2i)
No: 3+2i/3+2i

2) Fine, except for notation breakdown, again.

 

[Guest]

Ah, thanks.^^; I tend to be lazy when it comes to math. I'll remember to put in the parantheses next time.