Question

help on 3 questions?

Answer 1

(¬‿¬)

Answer 2

here are the 3 questions

Answer 3

idk from my question?

Answer 4

Why do you ask such simple questions :>

Answer 5

can u help me peter?

Answer 6

Waka waka waka waka waka waka waka

Answer 7

this time for...

anyway, sure, why not? ^.^

Answer 8

(5 - 5i) - (-6 - 3i)
This is just plain algebra isn't it?
Add and subtract like terms and all that?

Answer 9

wat?

Answer 10

wat?

Answer 11

let's pick another letter, maybe that 'i' has you thrown off or something... I choose p :D

What if it was (5 - 5p) - (-6 - 3p) instead, would it be a problem?

Answer 12

no thats pretty easy actually

Answer 13

Well then, show me, what's the answer if it were p instead?

Answer 14

just foil right?

Answer 15

To heck with foil, this is just subtraction!
(LOL and not multiplication ^.^ )

Answer 16

sorry im so lost its been a long day...........just subtract the 5p from 5? and the 3p from 6?

Answer 17

You can't subtract unlike terms, LOL

Answer 18

well can u explain in further detail what i am supposed to do?

Answer 19

Okay... how about an example? ^.^

Answer 20

(4 + 3i) - (-7 + i)

Answer 21

ok

Answer 22

First, get rid of the parentheses... the ones on the left, you can just do away with.
4 + 3i - (-7 + i)

Now, since it's a minus-sign in the middle, when you remove the parentheses on the right-side, you change the sign of everything inside:
4 + 3i + 7 - i

Now just combine like terms, the 4 and 7, as well as the 3i and -i

= 11 + 2i

get it?

Answer 23

yes so far.......go on.........

Answer 24

That's it.
You just apply the same principle to your question.

Answer 25

wait so thats the answer that simple?

Answer 26

that's the answer to my example. answering your question requires a similar process ^.^

Answer 27

ok let me solve those questions will u tell me if they are correct?

Answer 28

sure.

Answer 29

ok for #3 i got 11-2i right or wrong?

Answer 30

It's correct ^.^

Answer 31

ok but i tried to work out #4 but i dont get it can u help?

Answer 32

THAT's where you use FOIL.

Answer 33

ohhhhhh

Answer 34

Because it's multiplication.
Do remember that after the dust settles with your FOIL that
\[\Large i^2 = -1\]

Answer 35

sooooo now i have to multiply is by neg 1?

Answer 36

worry about that later, for now, just FOIL away.

Answer 37

i got \[-12i ^{2}-12i+16\]

Answer 38

now what?

Answer 39

a bit off... could you FOIL again? only this time, more carefully?

Answer 40

-4-4i?

Answer 41

that's strange, where did the i^2 go?
Don't skip steps LOL
That's how we go wrong :D

Answer 42

idk im so confused

Answer 43

i wll try again

Answer 44

-12i^2-4i+8?

Answer 45

That's good :)
NOW use the fact that \(\large i^2 = -1\) and simplify further ^.^

Answer 46

so multiply -12 times -1?

Answer 47

You got that right ^.^

Answer 48

You got your answer?

Answer 49

12-4i+8?

Answer 50

yes... go on... simplify the darn thing :>

Answer 51

simplifies to 20-4i

Answer 52

Now was that so hard? ;)

Answer 53

OHMEHFREAKINGGOOSENEEKS U ARE AMAZING PETER

Answer 54

Tell me something I don't know :)

Answer 55

ok on the last one i have to divide it? or what?

Answer 56

oh, division... this is the tricky one... but not that tricky.
ever heard of conjugates? :)

Answer 57

conjuwhats?

Answer 58

Conjugate of a complex number.
It sounds... complex, but it really isn't.

It just means you change the sign of the imaginary part.
For example:
conjugate of 1+3i is 1-3i
conjugate of 4 - i is 4+i
conjugate of 5i is -5i
conjugate of 7 is 7 (since there's no imaginary part)

In general, conjugate of a + bi is a - bi

get it?

Answer 59

so like the opposite of the first thing is the second?

Answer 60

uhh... don't confuse me with words like opposite... stick to conjugate in this context.
Here's a little drill...find the conjugates of these numbers:
1-2i
5+9i
7-i

Answer 61

1+2i
5-9I
7+1
?/???

Answer 62

Correct. See? Not very complex at all... ready to work on your third question now?

Answer 63

except for a few typos... it should be 7+i, not 7+1 -_-

Answer 64

sorry but i think i got it other than those pesky typos >:(

Answer 65

Okay, when dividing complex numbers. we don't want any i in the denominator.
So what we do is
\[\Large \frac{-6+i}{-5+i}\]

Answer 66

We multiply BOTH the numerator and denominator by the CONJUGATE of the denominator.
What's the conjugate of the denominator?

Answer 67

-5+i?

Answer 68

that's the denominator itself... but what's its CONJUGATE?
c'mon, you can do this ^.^

Answer 69

whoops i meant to say -5-i ;)

Answer 70

That's good. Now multiply both the numerator and denominator by that conjugate:
\[\Large \frac{-6+i}{-5+i}\times \frac{-5-i}{-5-i}\]
FOIL twice.

Just a heads' up: When you multiply a complex number by its own conjugate, you SHOULD get A REAL NUMBER. okay?
good.
Proceed...

Answer 71

Here, I'll make it simpler for you :)
\[\Large \frac{(-6+i)(-5-i)}{(-5+i)(-5-i)}\]

Answer 72

give meh a minute............

Answer 73

On the denominator, it might help you to remember that
\[\large (x+y)(x-y) = x^2-y^2\]

Answer 74

\[\frac{ 30+i }{ 25-i^2 }\]

is this right?

Answer 75

Denominator is correct... numerator... is not :D

By the way, you can further simplify the denominator... remember
\[\large i^2 = -1\]

Answer 76

let me try agian

Answer 77

Please do ^.^

Answer 78

-i^2-i+30?

Answer 79

Still no... please be very careful with signs :)
And please include your denominator too :)

Answer 80

ok im getting the same answer of 30+i-1^2/25-i^2 what am i doing wrong? :(

Answer 81

because your earlier numerator had a -i :P

Answer 82

is that 1^2?

Answer 83

sorry i mean i^2 im still getting used to using the i

Answer 84

Okay, now it's correct :)
\[\Large \frac{30+i-i^2}{25-i^2}\]
Now, simplify... and remember \[\large i^2=-1\]
finish it!

Answer 85

ok i can do this!

Answer 86

ALLEY

Answer 87

ISNT NICOLE PRETTY BEAUTIFUL C:

Answer 88

shhhhhhh im tryna learn

Answer 89

hah
Pan 1, Sky 0
:>

Answer 90

The Sky will fall upon you Peter :c

Answer 91

But today is not that day...
@tester97 got your answer yet? :D

Answer 92

is it \[\frac{ 31+i }{ 26}\]

Answer 93

hurrah :D

Answer 94

That wasn't so bad, was it? ^.^

Answer 95

:OIM FINALLY DONE THANKS SOOOOOOOOOOOOOOOO MUCH PETER!

Answer 96

No problem ^.^