Question

Help Rationalizing the denominator!

Answer 1

Something is wrong with this question?

Answer 2

No, I need help rationalizing the denominator.

Answer 3

No, it is supposed to have complex numbers at the bottom

Answer 4

$$\Huge \frac{\sqrt{-49}}{(7-2i)(4+9i)}$$

Answer 5

Yes

Answer 6

Use FOIL

Answer 7

I did I got 28+63i-8i-18i^2 as the denominator after foiling

Answer 8

So i^2 = -1

Answer 9

63i-8i=55i

Answer 10

So the -18i turns into positive 18i and combine it with 63i and -8i?

Answer 11

and 55i + 18i right?

Answer 12

-18i^2 = -18(-1)

Answer 13

oh yeah. I forgot to take off the i.

Answer 14

So combine the 18 with 28, right?

Answer 15

yes

Answer 16

Ok. So the denominator is 46+55i ?

Answer 17

yes

Answer 18

I should get 7i as the numerator?

Answer 19

plus or minus

Answer 20

plus?

Answer 21

$$\Huge\sqrt{-49}=\sqrt{-1*49}=7i$$

Answer 22

Oh ok. I thought it was supposed to be positive 7i.I have to use the conjugate of the complex number now on the fraction, yes?

Answer 23

i'm not sure what your question is asking, but yes you can multiply the numerator and the denominator by the conjugate...

Answer 24

Ok. Thanks.

Answer 25

Thanks for asking :)