Question

6i(4 - i^18)(3 - 7i^63) heeeelllllppp

Answer 1

What are you having trouble with?

Answer 2

i think i got the answer but im not sure if its right. i got 72i - 168i^64 - 18i^19 + 42i^82

Answer 3

Well, we can simplify that, right? what is i^64?

Answer 4

1?

Answer 5

Right, how did you get that?

Answer 6

Anyways, simplify your i terms first, then multiply out your expression.

Answer 7

i divided 64 by 4 and used the little i circle thing to count around 16 times

Answer 8

can i do that last or should do that first?

Answer 9

It will make it easier, and you will have less chance of making a mistake if you simplify your i terms first.

Answer 10

so i got a final answer of 72i-168 +18i -42

Answer 11

is that right?

Answer 12

90i - 210 actually

Answer 13

or -90 - 210 because when combining two i's it becomes i^2

Answer 14

6i(4 - i^18)(3 - 7i^63)=6i(4-(-1))(3-(-i))=6i(5)(3+i)=30i(3+i)=90i-30

Answer 15

So, not quite. You probably made a little arithmetic error somewhere.

Answer 16

wait so how did you go from 3 - 7i^63 to 3 + i? what happened to the 7?

Answer 17

I'm terribly sorry. I appear to have made the error.

Answer 18

dfyodor, did a boo boo.

Answer 19

90i-210*

Answer 20

Ammend the above to read:
6i(4 - i^18)(3 - 7i^63)=6i(4-(-1))(3-7(-i))=6i(5)(3+7i)=30i(3+7i)=90i-210

Answer 21

okay awesome, got it!