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Divide. 

(6i)/(5-4i)=?

 Dec 10, 2014

Best Answer 

 #2
avatar+26400 
+5

Divide.  (6i)/(5-4i)=  ?

$$\small{\text{
$ \dfrac{6i}{5-4i} \times \dfrac{5+4i}{5+4i} $
}}$\\\\$\small{\text{
$ = \dfrac{6i*(5+4i)}{(5-4i)(5+4i)} $
}}$\\\\$\small{\text{
$ = \dfrac{30i+24i^2}{25-16i^2} \quad \boxed{ i^2 = -1 } $
}}$\\\\$\small{\text{
$ = \dfrac{30i-24}{25+16} $
}}$\\\\$\small{\text{
$ = \dfrac{30i-24}{41} $
}}$\\\\$\small{\text{
$ = -\dfrac{24}{41} + \dfrac{30}{41}i $
}}$$

 Dec 11, 2014
 #1
avatar+118723 
+5

$$\\\frac{(6i)}{(5-4i)}\times \frac{(5+4i)}{(5+4i)}\\\\
=\frac{6i(5+4i)}{25--16}\\\\
=\frac{30i-24}{41}\\\\
=\frac{-24}{41}+\frac{30}{41}\;i$$

 

A small error has been repaired :)

 Dec 10, 2014
 #2
avatar+26400 
+5
Best Answer

Divide.  (6i)/(5-4i)=  ?

$$\small{\text{
$ \dfrac{6i}{5-4i} \times \dfrac{5+4i}{5+4i} $
}}$\\\\$\small{\text{
$ = \dfrac{6i*(5+4i)}{(5-4i)(5+4i)} $
}}$\\\\$\small{\text{
$ = \dfrac{30i+24i^2}{25-16i^2} \quad \boxed{ i^2 = -1 } $
}}$\\\\$\small{\text{
$ = \dfrac{30i-24}{25+16} $
}}$\\\\$\small{\text{
$ = \dfrac{30i-24}{41} $
}}$\\\\$\small{\text{
$ = -\dfrac{24}{41} + \dfrac{30}{41}i $
}}$$

heureka Dec 11, 2014

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