3log12+3log9-3log4+3log3

³㏒(12.9/4.3)=³㏒81=³㏒3⁴=4.³㏒3=4.1=4

= 3log12 + 3log9 – 3log4 + 3log3
= 3log4×3 + 3log3^2 – 3log4 + 1 (aloga = 1)
= 3log4+3log3 + 2 3log3 – 3log4 + 1 {(alogb+c = alogb + alogc) dan (aloga^n = n aloga)}
= 3log4 + 1 + 2 × 1 – 3log4 + 1
= 3log4 + 1 + 2 – 3log4 + 1
= 3log4 – 3log4 + 4
= 4

maap kalau misalnya ada yang silap