Question

Does anybody know how to find what is an equivalent form of 5+2i/3i?

The choices are:
a)2-5i/-3
b)-2+5i/3
c)-2-5i/-1
d)2-5i/3

(oh and can you also show how you got the answer please?)

Answer 1

To rationalize the denominator, you multiply both top and bottom by the conjugate of the denominator.

The conjugate of 3i is -3i

Answer 2

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

Answer 3

Tell me what you get when you do this

Answer 4

well, 3i and -3i would make -9i^2 which turns into -10

Answer 5

To me, I just time i to both numerator and denominator

Answer 6

well yes, but when you times it, ohh, ok I think I multiplied wrong

Answer 7

-9i^2 = -9(-1) = 9

So -9i^2 = 9

Answer 8

oh yes, um when I mutiplied I got -25i-6i^2/-9i^2, then I simplified that into -15i-7/-10

Answer 9

oh, that's why, because I added -1 instead of multiplying it

Answer 10

oh, ok thank-you, again lol

Answer 11

In the numerator, you will have

(5+2i)*(-3i) = -3i(5+2i)

(5+2i)*(-3i) = -3i(5)-3i(2i)

(5+2i)*(-3i) = -15i - 6i^2

and I'll let you finish