jika 2 log5=p dan 3 log5=g nyatakan 30 log 150 dalam p dan g

2log5 = p
5log2 = 1/p
3log5 = g
5log3 = 1/g

30log150 = log150 / log30
= log5² x 6 / log 5 x 6
= log5² + ( log 3 + log2) / log5 + (log3 + log2)
= 2 5log5 + (5log3 + 5log2) / 5log5 + (5log3 + 5log2)
= 2(1) + (1/g + 1/p) / 1 + (1/g + 1/p)
= 2 + ( p+g / pg) / 1 + (p+g / pg)