Ask your own question, for FREE!
Mathematics 17 Online
OpenStudy (anonymous):

simplify the expression below

OpenStudy (anonymous):

\[\frac{ -5+i }{ 2i }\]

OpenStudy (ranga):

Multiply the top and bottom by i

OpenStudy (anonymous):

\[\frac{ -10i+2i }{ 4i }\] i tried, but i have no idea if thats right though..

OpenStudy (anonymous):

oh wait i wasnt supposed to multiply by 2i???

OpenStudy (ranga):

You can but the 2 will can be factored out and canceled. So multiply by i is better. Also i times i = i squared = -1

OpenStudy (anonymous):

@agent0smith

OpenStudy (anonymous):

im still confused!

OpenStudy (ranga):

\[\frac{ -5 + i }{ 2i } \times \frac{ i }{ i } = \frac{ -5i + i ^{2} }{ 2i ^{2} }\]

OpenStudy (ranga):

\[i = \sqrt{-1}\]\[i ^{2} = -1\]

OpenStudy (shamil98):

i^2 = -1. then as ranga put just simplify the values from there -5i + (-1) / 2(-1)

OpenStudy (anonymous):

ok i understand that part, im just exactly sure how to simplify it now.

OpenStudy (ranga):

\[\frac{ -5i + i ^{2} }{ 2i ^{2} } = \frac{ -5i - 1 }{ -2 } = \frac{ 1 + 5i }{ 2 }\]

OpenStudy (anonymous):

how did they become positive?

OpenStudy (ranga):

Factor out -1 from top and bottom and they will cancel out.

OpenStudy (ranga):

For example: -5 / -3 = 5 / 3

OpenStudy (anonymous):

how did you get the three?

OpenStudy (ranga):

I was just giving an example of dividing two negative numbers and how the negatives will cancel out.

OpenStudy (ranga):

\[\frac{ -5i - 1 }{ -2 } = \frac{ (-1)(5i + 1) }{ -1(2)} = \frac{ 1+ 5i }{ 2 }\]

OpenStudy (anonymous):

now what do i do?

OpenStudy (ranga):

That is it. You have simplified the expression. You have gotten rid of the i in the denominator.

OpenStudy (anonymous):

there is nothing more that you can do to simplify it?

OpenStudy (ranga):

If you want you can write it as:\[\frac{ 1 + 5i }{ 2 } = \frac{ 1 }{ 2 } + \frac{ 5i }{ 2 }\]

OpenStudy (anonymous):

but either one is considered correct?

OpenStudy (ranga):

Is the answer different from any of the above?

OpenStudy (anonymous):

no? haha

OpenStudy (anonymous):

ok i got it, thank you!

OpenStudy (ranga):

you are welcome.

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!