Solving equations via substitution

[jackscholar]

I am trying to solve an equation that involves substitution.

I was given k= 7 in the equation n=k+c
i was also given n=2^c-1
I figured that 7+c could be substituted into the equation as n, so I got
7+c=2^c-1 and therefore c=2^c-8.
The problem is that the answer I want is c=4...but substituting 4 as C does not give me a correct answer. Any help would be greatly appreciated.
Thank you

 

[Stephen Tashi]

Maybe the probem should say n = k + 2c

 

[jackscholar]

This pertains to hamming codes, so n is the total number of bits, k is the amount of information digits and c is the amount of check digits. I was given another example aswell. This example says: Suppose there are four information digits.
Then n=4+c
and n=2^c-1
then 4+c=2^c-1
hence c=2^c-5

 

[Stephen Tashi]

I was given k= 7 in the equation n=k+c
i was also given n=2^c-1

This pertains to hamming codes

The inequation I see on the web for hamming codes is [itex] n \le 2^c -1 [/itex]

 

[CellCoree]

for reaching out for help with this equation. It seems that you have correctly substituted 7+c for n in the first equation. However, when you substituted 4 for c in the second equation, you may have made a mistake in your calculations. I would suggest double checking your work to see if you can identify where the error occurred. Additionally, it may be helpful to try solving the equation using a different method, such as graphing or using algebraic manipulations, to see if you arrive at the correct answer of c=4. If you are still having trouble, please feel free to provide more information or equations and I would be happy to assist further.