SOLUTION: Given 2^x=3^y=5^z=900^w Show that: xyz=2w(xy+yz+xz)

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Question 770321: Given 2^x=3^y=5^z=900^w
Show that:
xyz=2w(xy+yz+xz)

Found 2 solutions by Edwin McCravy, AnlytcPhil:
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
Given 2^x=3^y=5^z=900^w
Show that:
xyz=2w(xy+yz+xz)
Suppose that 

2x = 3y = 5z = 900w = A

Then,

ln(2x) = ln(3y) = ln(5z) = ln(900w) = ln(A)

x·ln(2) = y·ln(3) = z·ln(5) = w·ln(900) = ln(A)

x=ln%28A%29%2Fln%282%29, y=ln%28A%29%2Fln%283%29, z=ln%28A%29%2Fln%285%29, w=ln%28A%29%2Fln%28900%29

*** xyz = ln%28A%29%2Fln%282%29%22%22%2A%22%22ln%28A%29%2Fln%283%29%22%22%2A%22%22ln%28A%29%2Fln%285%29 = %28ln%28A%29%29%5E3%2F%28ln%282%29ln%283%29ln%285%29%29***       

xy = %28ln%28A%29%2Fln%282%29%29%22%22%2A%22%22%28ln%28A%29%2Fln%283%29%29 = %28ln%28A%29%29%5E2%2F%28ln%282%29ln%283%29%29

yz = %28ln%28A%29%2Fln%283%29%29%22%22%2A%22%22%28ln%28A%29%2Fln%285%29%29 = %28ln%28A%29%29%5E2%2F%28ln%283%29ln%285%29%29

xz = %28ln%28A%29%2Fln%282%29%29%22%22%2A%22%22%28ln%28A%29%2Fln%285%29%29 = %28ln%28A%29%29%5E2%2F%28ln%282%29ln%285%29%29  

xy + yz + xz = %28ln%28A%29%29%5E2%2F%28ln%282%29ln%283%29%29%22%22%2B%22%22%28ln%28A%29%29%5E2%2F%28ln%282%29ln%283%29%29%22%22%2B%22%22%28ln%28A%29%29%5E2%2F%28ln%282%29ln%283%29%29%22%22=%22%22

          %22%22=%22%22

w%22%22=%22%22ln%28A%29%2Fln%28900%29%22%22=%22%22ln%28A%29%2Fln%282%5E2%2A3%5E2%2A5%5E2%29%22%22=%22%22ln%28A%29%2F%28ln%282%5E2%29%2Bln%283%5E2%29%2Bln%285%5E2%29%29%22%22=%22%22ln%28A%29%2F%282ln%282%29%2B2ln%283%29%2B2ln%285%29%29%22%22=%22%22

          ln%28A%29%2F%282%28ln%282%29%2Bln%283%29%2Bln%285%29%29%29

So 2w = 2ln%28A%29%2F%282%28ln%282%29%2Bln%283%29%2Bln%285%29%29%29%22%22=%22%22cross%282%29ln%28A%29%2F%28cross%282%29%28ln%282%29%2Bln%283%29%2Bln%285%29%29%29%22%22=%22%22ln%28A%29%2F%28ln%282%29%2Bln%283%29%2Bln%285%29%29   
    
2w(xy+yz+xz)%22%22=%22%22ln%28A%29%2F%28ln%282%29%2Bln%283%29%2Bln%285%29%29%22%22%2A%22%22%22%22=%22%22

          ln%28A%29%2F%28cross%28ln%282%29%2Bln%283%29%2Bln%285%29%29%29%22%22%2A%22%22%22%22=%22%22%28ln%28A%29%29%5E3%2F%28ln%282%29ln%283%29ln%285%29%29

And that's what xyz was shown equal to above, marked ***      

Edwin

Answer by AnlytcPhil(1806) About Me  (Show Source):
You can put this solution on YOUR website!
Given 2^x=3^y=5^z=900^w
Show that:
xyz=2w(xy+yz+xz)
Suppose that

2x = 3y = 5z = 900w = A

Then (you can also use log instead of ln, as above):

log(2x) = log(3y) = log(5z) = log(900w) = log(A)

x·log(2) = y·log(3) = z·log(5) = w·log(900) = log(A)

x=log%28A%29%2Flog%282%29, y=log%28A%29%2Flog%283%29, z=log%28A%29%2Flog%285%29, w=log%28A%29%2Flog%28900%29

*** xyz = log%28A%29%2Flog%282%29%22%22%2A%22%22log%28A%29%2Flog%283%29%22%22%2A%22%22log%28A%29%2Flog%285%29 = %28log%28A%29%29%5E3%2F%28log%282%29log%283%29log%285%29%29***

xy = %28log%28A%29%2Flog%282%29%29%22%22%2A%22%22%28log%28A%29%2Flog%283%29%29 = %28log%28A%29%29%5E2%2F%28log%282%29log%283%29%29

yz = %28log%28A%29%2Flog%283%29%29%22%22%2A%22%22%28log%28A%29%2Flog%285%29%29 = %28log%28A%29%29%5E2%2F%28log%283%29log%285%29%29

xz = %28log%28A%29%2Flog%282%29%29%22%22%2A%22%22%28log%28A%29%2Flog%285%29%29 = %28log%28A%29%29%5E2%2F%28log%282%29log%285%29%29

xy + yz + xz = %28log%28A%29%29%5E2%2F%28log%282%29log%283%29%29%22%22%2B%22%22%28log%28A%29%29%5E2%2F%28log%282%29log%283%29%29%22%22%2B%22%22%28log%28A%29%29%5E2%2F%28log%282%29log%283%29%29%22%22=%22%22

          %22%22=%22%22

w%22%22=%22%22log%28A%29%2Flog%28900%29%22%22=%22%22log%28A%29%2Flog%282%5E2%2A3%5E2%2A5%5E2%29%22%22=%22%22log%28A%29%2F%28log%282%5E2%29%2Blog%283%5E2%29%2Blog%285%5E2%29%29%22%22=%22%22log%28A%29%2F%282log%282%29%2B2log%283%29%2B2log%285%29%29%22%22=%22%22

          log%28A%29%2F%282%28log%282%29%2Blog%283%29%2Blog%285%29%29%29

So 2w = 2log%28A%29%2F%282%28log%282%29%2Blog%283%29%2Blog%285%29%29%29%22%22=%22%22cross%282%29log%28A%29%2F%28cross%282%29%28log%282%29%2Blog%283%29%2Blog%285%29%29%29%22%22=%22%22log%28A%29%2F%28log%282%29%2Blog%283%29%2Blog%285%29%29

2w(xy+yz+xz)%22%22=%22%22log%28A%29%2F%28log%282%29%2Blog%283%29%2Blog%285%29%29%22%22%2A%22%22%22%22=%22%22

          log%28A%29%2F%28cross%28log%282%29%2Blog%283%29%2Blog%285%29%29%29%22%22%2A%22%22%22%22=%22%22%28log%28A%29%29%5E3%2F%28log%282%29log%283%29log%285%29%29

And that's what xyz was shown equal to above, marked ***

Edwin