Mathematics
4 Online
OpenStudy (anonymous):
How to simplify: (1-3i)(2+i)/(2-i) ?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (luigi0210):
\[\frac{ (1-3i)(2+i) }{ 2-i }\]
OpenStudy (luigi0210):
Is that it?
OpenStudy (anonymous):
yes! @Luis_Rivera
OpenStudy (luigi0210):
Well then all you do is FOIL the top
OpenStudy (anonymous):
I got 5(I+1)/(2-i) so far
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
@Luigi0210 would this be one of those situtations when you may mulitply by the reciprical "2+i"..?
OpenStudy (luigi0210):
You could just leave it as \[\frac{ 5-5i }{ 2-i }\]
OpenStudy (luigi0210):
*conjugate, and yes sir!
OpenStudy (luigi0210):
So just as viper says, multiply the top and bottom by the conjugate of 2+i
OpenStudy (anonymous):
@Luigi0210 Are you sure you cant simplify it because my teacher did (?... (-2) ) .. He took off points for not simplifying
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
OH I just saw that okay so 5(I+1)(2+i)
OpenStudy (luigi0210):
\[\frac{ 5-5i }{ 2-i }*\frac{ 2+i }{ 2+i }=\frac{ 10+5i-10i-5i^2 }{ 4-i^2 }\]
Can you finish it from here Miss Princess?
OpenStudy (anonymous):
(1 - 3i) x 2 + i / 2 - i = 3 - 1
OpenStudy (anonymous):
@Luigi0210 Oh sorry I forgot! Yea ..
OpenStudy (anonymous):
then youd combine like terms
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
would you expand the denom.
OpenStudy (luigi0210):
\[i^2=-1\]
OpenStudy (anonymous):
Did you get -5i+15/5 ??
OpenStudy (luigi0210):
Yup, and simplified down farther it is 3-i.
OpenStudy (luigi0210):
*or -i+3
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
Haha yea it's 3 - i
OpenStudy (anonymous):
The works up there sorry I don't want to post it again haha!
OpenStudy (luigi0210):
What up pooper? :D
OpenStudy (anonymous):
Nothing I'm just bored so I decided to help people with math :/ haha
Marios bro
OpenStudy (luigi0210):
Ah, interesting
I know :P
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
Haha!
OpenStudy (anonymous):
I'm going to continue on now! :D
OpenStudy (luigi0210):
ha, well alright.. good day to you :P
OpenStudy (anonymous):
thnx!
OpenStudy (anonymous):
You too luigi! :*
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (luigi0210):
No problem :P Enjoy the rest of your day you two :P