Question

\[10-20i/3-i\]

Answer 1

you need to get the i out of the denominaator by using conjugates

Answer 2

how do I do i get the (i) out?, im trying to take the notes so I will understand on the test how to do it?

Answer 3

you have 3-i in the denom, right?

Answer 4

?

Answer 5

yes 3-i

Answer 6

multiply (3-i) times (3+i) and tell me what you get

Answer 7

9 -i^2

Answer 8

what is i^2?

Answer 9

to the second power

Answer 10

I know but i=sqrt -1. so what is i^2?

hint:\[\sqrt{x}*\sqrt{x}=\left( \sqrt{x} \right)^{2}=x\]

Answer 11

still there?

Answer 12

9-i

Answer 13

im sorry im lost lol

Answer 14

no but close. i^2=-1
so9-(-1)=10

so you have the i out of the denominator. but you have to do the same thing to the numerator--ok?

Answer 15

ok

Answer 16

(30-i)(30+i)

Answer 17

so it will be (10-20i)(3+i)/10
10+10i-60i-20i^2/10
10-50i-20(-1)/10
10-50i+20/10
3-5i

Answer 18

this is the do the same to the top as you do on the bottom?

Answer 19

yes or you r changing the fraction. The key to this problem is that comlex numbers (numbers with an i in them) are not in standard form if there is an I in the denom..
So I showed you what to multiply the denom by in order to get rid of the i. but you must then multiply the numerator by the same thing and then simplify

Answer 20

ok or do you need more explanation cause I am moving on otherwise

Answer 21

im good, ty so much, that was the first problem I had an (i) with ever, i didnt know it ment sq rt

Answer 22

great

Answer 23

:) ty