2log 3 = a dan 2log 5 = b nilai 5log 30 =

²log3 = a
²log5 = b

Jwb:
⁵log30
= log30 / log5
= log(2.3.5) / log5
= (²log2 + ²log3 + ²log5) / ²log5
= (1 + a + b) / b
= (a + b + 1) / b