Question

Write the expression in standard form.
5/3-15i

Answer 1

you'll want to multiply by the conjugate of the denominator. notice we are basically multiplying by 1.

\[\frac{ 5 }{ 3 - 15i } = \frac{ 5 }{ 3 - 15i }\frac{ 3 + 15i }{ 3 + 15i }\]

now we got i out of the denominator (since we're left with constants and i^2)

it's ok to have i in the numerator.

solve/expand like the last problem :)

Answer 2

you good with this?

Answer 3

I'm not sure yet

Answer 4

My answers are:
5/78-25/78i
5/78+25/78i
-5/78+25/78i
-5/78-25/78i

Answer 5

I am so not good with this.

Answer 6

those are the answers you got, or the answer choices they gave you?

Answer 7

The ones they gave me.

Answer 8

I think the i's are supposed to go with the top numbers...

Answer 9

\[\frac{ 5 }{ 3-15i }\frac{ 3+ 15i }{ 3 + 15 i }\]

\[\frac{ 15+ 75i }{ 9-225(-1) }\]

Answer 10

They are just out to the side of the fraction in the problem

Answer 11

do you see where I got this?

Answer 12

Yes

Answer 13

\[\frac{ 15 + 75i }{ 9+225 }\]

\[\frac{ 15 + 75i }{ 234 }\]

\[\frac{ 15 }{ 234 }+ \frac{ 75i }{ 234 }\]

how about this

Answer 14

Yes

Answer 15

\[\frac{ 15 }{ 234 }+\frac{ 75 }{ 234 }i\]

\[\frac{ 5 }{ 78 }+ \frac{ 25 }{ 78 }i\]

and now this?

Answer 16

No, you lost me.

Answer 17

I just reduced the fractions... What number divides evenly in both 15 and 234?

3

15 div 3 5
---
234 div 3 78

Answer 18

75 div 3 25
-- ---
234 div 3 78

Answer 19

Okay, I've got you now. Thank you so much!

Answer 20

yw