Diketahui 2log3 = m dan 2 log5= n. Nilai 2log90 adalah....

²log90 = ²log(2 x 9 x 5)
           = ²log2 + ²log9 + ²log5
           = ²log2 + ²log3² + ²log5
           = ²log2 + 2. ²log3 + ²log5
           = 1 + 2m + n
           = 2m + n + 1 

²log 3 = m
²log 5 = m

²log90
= ²log(9 . 2 . 5)
= ²log3² + ²log2 + ²log5
= 2. ²log3 + 1 + ²log5
= 2m + 1 + n
= 2m + n + 1