Jika 2log3=x dan 5 log 2=y maka 8log75 adalah
^8log75, misal ubah pd basis 2
= ^2log75/^2log8
= ^2log(3.5^2)/^2log(2^3)
= (^2log3 + 2.^2log5)/(^2log2 + ^2log3)
= (x + 2/^5log2)/(1 + x)
= (x + 2/y)/(1 + x)
= ((xy + 2)/y) / (1 + x)
= (xy + 2)/[y(1 + x)]