SOLUTION: convert the following in base ten to decimal (a.)(3 7/8) (b.) 321n = 232seven find n

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Question 894942: convert the following in base ten to decimal
(a.)(3 7/8)
(b.) 321n = 232seven find n
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
321%5Bn%5D+=+232%5Bseven%5D

3n%5E2%2B2n%2B1+=+2%2A7%5E2%2B3%2A7%2B2

3n%5E2%2B2n%2B1+=+98%2B21%2B2

3n%5E2%2B2n%2B1+=+121

3n%5E2%2B2n+=+120

3n%5E2%2B2n-120=0

%283n-20%29%28n-6%29=0

3n-20=0;    n-6=0
    n=20%2F3; n=6

n is an integer so n=6

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Checking:

3n%5E2%2B2n%2B1+=+2%2A7%5E2%2B3%2A7%2B2

3%286%29%5E2%2B2%286%29%2B1+=++121

3%2836%29%2B12%2B1+=++121

121=121

Edwin