Question

okay help with this problem and then one more and I wont need anymore help tonight.

(2-3i(3-i)-(4-i)(4+i)

Answer 1

\[(2-3i)(3-i)-(4-i)(4+i)\]

Answer 2

(2-3i)(3-i)-(4-i)(4+i)

Answer 3

theres supposed to be one more parenthases after 3i

Answer 4

am i foiling this or is that not the right way to go about this problem?

Answer 5

you can FOIL or use the table like last time. Which option works best for you?

Answer 6

foil the table is a little confusing.

Answer 7

ok what do you get when you FOIL (2-3i)(3-i)

Answer 8

(2 -3i)(3-i)-(4-i)(4+i)
(2)(3-i)-(3i)(3-i)-(4^2-i^2)
Multiply find the value
Note i^2 = -1
Source: mathskey.com

Answer 9

3-11i

Answer 10

correct

Answer 11

how about `(4-i)(4+i)` ?

Answer 12

that is 15

Answer 13

brb

Answer 14

not 15, but you are close

Answer 15

try again

Answer 16

okay

Answer 17

where did i go wrong with my problem i will show you my work.

Answer 18

(4-i)(4+i)
(a-b)(a+b) =a^2-b^2
4^2 -i^2
16-(-1)=17

Answer 19

could the answer be 187i+51?

Answer 20

i^2 is -1

so \(\Large 16-\color{red}{i^2}\) turns into \(\Large 16-\color{red}{(-1)}\)

Answer 21

im not sure @sayomi

Answer 22

Do you see what I mean @huntergirl1 ?

Answer 23

yes now i do @jim_thompson5910

Answer 24

ok great, so

16-(-1) = 16+1 = 17

---------------------

\[\large \color{red}{(2-3i)(3-i)}-\color{blue}{(4-i)(4+i)} =\color{red}{3-11i}-\color{blue}{17} = -14-11i\]

Answer 25

@sayomi you were correct and yes @jim_thompson5910 i do understand

Answer 26

I'm glad it's making sense

Answer 27

so the ending result is 51-187i

Answer 28

okay do you wnt me to start a new window for the next problem? or to place it here?

Answer 29

how are you getting `51-187i` ?

Answer 30

I wrote the answer above

Answer 31

bc you put 17 back into the problem

Answer 32

are you saying that they wanted you to multiply `(2-3i)(3-i)` and `(4-i)(4+i)` ??

Answer 33

actually i put those answers both into the website they were both incorrect

Answer 34

hwy was the answer supposed to be -14-11i?

Answer 35

why

Answer 36

because the 3 and -17 combine to -14

Answer 37

(3-11i) - (17) = 3-11i - 17 = (3-17) + (-11i) = -14 - 11i

Answer 38

oh okay.

Answer 39

will you be on to check a few more problems before I submit them?

Answer 40

sure

Answer 41

thank you!!!!!!!!!!!!

Answer 42

no problem

Answer 43

okay i have one to check its similar to the last problem

Answer 44

what did i do wrong?

Answer 45

you didn't foil correctly

Answer 46

okay i guess the sqrt part mixed me up

Answer 47

i also tried the box method too

Answer 48

what we do is make a 2x2 box

2 rows and 2 columns

the terms of each factor will go along the outside like this