SOLUTION: how do you get the quotient for -9/i in the form a + bi and how do you get the quotient for 9+3i _

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Question 267876: how do you get the quotient for -9/i in the form a + bi
and
how do you get the quotient for

9+3i
_____
4 -8i

Found 3 solutions by stanbon, Alan3354, josmiceli:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
how do you get the quotient for
-9/i in the form a + bi
----
Multiply numerator and denominator by "i" to get:
-9i/(-1)
= 9i
= 0+9i
-------------------
and
how do you get the quotient for
(9+3i)/(4 -8i)
---
Multiply numerator and denominator by 4+8i to get:
[(4+8i)(9+3i)]/[16+64]
---
= [36-24+72i+12i]/80
-----
= [12+84i]/80
Reduce to get:
= [3 + 21i]/20
==================
Cheers,
Stan H.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
how do you get the quotient for -9/i in the form a + bi
Multiply NUM and DEN by i
= -9i/i^2
= 9i
It is in a + bi form, a = 0
--------------------------
how do you get the quotient for
9+3i
_____
4 -8i
------------
Multiply NUM and DEN by the conjugate of the DEN 4+8i
= (9+3i)*(4+8i)/(16+64)
= (12 + 84i)/80
= (3+21i)/20
or (3/20)*(1+7i)

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
-9%2Fi
Multiply top and bottom by i
%28-9%2Fi%29%2A%28i%2Fi%29
%28-9i%29%2Fi%5E2
%28-9i%29%2F%28-1%29
9i
0+%2B+9i answer
----------------
%289+%2B+3i%29%2F%284+-+8i%29
Multiply top and bottom by 4+%2B+8i
%28%289+%2B+3i%29%2F%284+-+8i%29%29+%2A+%28%284+%2B+8i%29%2F%284+%2B+8i%29%29
%28%289+%2B+3i%29%2A%284+%2B+8i%29%29%2F%28%284+%2B+8i%29%284+-+8i%29%29
%2836+%2B+12i+%2B+72i+-+24%29%2F%2816+%2B+32i+-+32i+%2B+64%29
12+%2B+84i%29%2F80
%283%2F20%29+%2B+%2821%2F20%29i