Complex number calculation in algebraic form with substitution

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Purpleshinyrock
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Hello, I have this (I am solving scholarship exams)math problem and I don't quite know what to do with it , Could You please help?

The exercise is about complex numbers and it says:
Calculate
Math expression: ((w - 1)/2) raised to the power 7, multiplied by 10/z.
in the algebraic form(a+bi)

I thought on applying substitution since -1=i^2 and z is the real part but don't know what to do with the w.
Heres the solution:
Worked solution in LaTeX: ((w-1)/2)^7 × 10/z = ((2i)/2)^7 × 10/(1+3i) = -i × 10/(1+3i) = -i × (10/(1+3i)) × (1-3i)/(1-3i) = -10i/10 (1-3i) = 3 - i.
 
jedishrfu said:
The first image appears to be a broken link and so we can't really help you with this yet.
I am sorry.
This is the image
Mathematical expression: ((w - 1)/2)^7 × 10/z
 
yes
PeroK said:
I assume you are given ##w## and ##z##?
w=1´+2i and z=1+3i
 
Purpleshinyrock said:
yes

w=1´+2i and z=1+3i
Okay, what don't you understand about the given solution?
 
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Purpleshinyrock said:
w=1´+2i and z=1+3i
That would have been valuable information in the first post.
The solution just plugs that into the expression and then simplifies.
 
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PeroK said:
Okay, what don't you understand about the given solution?
I thought I needed to apply a concept of complex numbers , I am so sorry I did what you where implying and got to the result I din't think of the pluggin the values in.
 
Purpleshinyrock said:
I thought I needed to apply a concept of complex numbers , I am so sorry I did what you where implying and got to the result I din't think of the pluggin the values in.
Yes, that's all there is to it.
 
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One property you need to know is that i^2=-1 so you can use this to simplify the power expression. You also need to know about complex conjugation.
 
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