Question

Evaluate the expression and write the result in the form
a + bi.

(9 + 3i)(3 − i) over/
3 + i

Answer 1

\[\frac{(9+3i)(3-i)}{3+i}\times\frac{3-i}{3-i}\]

Answer 2

I got that far

Answer 3

whats next?

Answer 4

\[\frac{(27-9i+9i-3i^2)*(3-i)}{9-i^2}\]

Answer 5

\[\frac{(27-(3*-1)*(3-i)}{9-(-1)}\]

Answer 6

\[\frac{(27+3)*(3-i)}{10}=\frac{90-30i}{10}\]

Answer 7

oops i forgot to click post lol

Answer 8

i had something different

Answer 9

\[9-3i\]

Answer 10

\[\frac{(9+3i)(3-i)}{3+i}=\frac{27-9i+9i-3i^2}{3+i}=\frac{27-3(-1)}{3+i}=\frac{30}{3+i}\]
\[=\frac{30}{3+i}*\frac{3-i}{3-i}=\frac{90-30i}{9-i^2}=\frac{90-30i}{9-(-1)}=\frac{90-30i}{10}\]
no you are right

Answer 11

I check it correct answer
http://www.mathway.com/answer.aspx?p=calg?p=((9+3i)(3-i))SMB10(3+i)?p=22?p=?p=?p=?p=?p=0?p=?p=0?p=?p=

Answer 12

=9-3i

Answer 13

i couldn't remember what i had before i forgot to click post lol

Answer 14

ty