Jika diketahui 2log 3 = x dan 3log 7 = y maka 56log 14 =...

2log 3 = x dan 3log 7 = y,
56log 14 = log 14 / log 56
= log (2.7) / log (8.7)
= (log 2 + log 7) / (log 8 + log 7)
= (log 2 + log 7) / (log 2^3 + log 7)
= (log 2 + log 7) / (3. log 2 + log 7)
beri bilangan pokok logariitma 3. maka
= (3log 2 + 3log 7) / (3. 3log 2 + 3log 7)
= (1/x + y ) / (3.1/x + y)
= (xy + 1)/x / (xy + 3)/x
= (xy + 1) / (xy + 3)