jika log 2=p ,log 3=q dan log 5=r, nyatakan ^18log 108 p,q,r

log 2 = p
log 3 = q
log 5 = r

^18log 108
= ^18log (4.27)
= ^18log 4 + ^18log 27
= ^18log 2² + ^18log 3³
= 2. ^18log 2 + 3. ^18log 3
= 2 (1 / ^2log 18) + 3 (1 / ^3log 18)
= 2 (1 / ^2log 18)(log 2 / log 2) + 3 (1 / ^3log 18)(log 3 / log 3)
= 2 (log 2 / log 18) + 3 (log 3 / log 18)
= 2 (log 2 / log (2.3²) + 3 (log 3 / log (2.3²))
= 2 (p / (p + 2q)) + 3 (q / (p + 2q))
= 2p/(p + 2q) + 3q/(p + 2q)
= (2p + 3q)/(p + 2q)