1/p + 1/k = 4/9
p+k=12
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(p+k)/pk =4/9
p+k=12
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9(p+k)=4pk , 9.12=4pk, 27=pk
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p+k=12
pk=27, pk=3.9, 3+9=12
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/p,k/=/3,9/ ili /p,k/=/9,3/
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