Jika 2log5=a dan 2log3 = b , maka 2log(1,8) = …

²log1,8
= ²log18/10
= ²log9/5
= ²log9 - ²log5
= ²log3² - ²log5
= 2(²log3) - ²log5
= 2b - a

#semoga membantu

Kelas 10 Matematika
Bab Logaritma

²log 1,8
= ²log (18/10)
= ²log 18 - ²log 10
= ²log (2 . 3²) - ²log (5 . 2)
= (²log 2 + ²log 3²) - (²log 5 + ²log 2)
= (1 + 2 . ²log 3) - (a + 1)
= (1 + 2b) - a - 1
= 2b - a