## blahblah_who_cares 2 years ago Divide: (12+9i)/(3-4i)

1. Azteck

$\frac{ 12+9i }{ 3-4i }\times \frac{ 3+4i }{ 3+4i }=\frac{ (12+9i)(3+4i) }{ 9+16 }$

2. Azteck

Rationalise the denominator mate....

3. blahblah_who_cares

Thanks forgot about that. U cant have i in the denominator. i was using long division. fail.

4. Azteck

Mate. If you need the answer to refer to when you do it. Here's what you want to get as your answer. 3i is the answer.

5. blahblah_who_cares

I knew what the answer was. I just forgot how to get it.

6. Azteck

ah okay, no worries then.

7. blahblah_who_cares

Can you help me with one more problem?

8. blahblah_who_cares

How do i find an absolute value of a binomial with an i?

9. Azteck

absolute value of a complex number means the distance of the curve of the complex number. To find the distance of complex number curve, you just use pythagoras... $\left| a+ib \right|=\sqrt{a^2+b^2}$

10. blahblah_who_cares

So "i" just disappears?

11. Azteck

Dude haven;t you learnt about absolute values? The absolute value of something is the distance from the origin.

12. Azteck

You're finding the distance from the origin to to the point (a, b)

13. Azteck

@blahblah_who_cares