1.nilai dari 2 log6+2 log12-2 log9 adalah?2.2 log27 . 3 log8 adalah?
Sama dgn 2 log (6×12:9)=2 log8=2log 2^3=3
1)
2 log 6 = 2 log 2 x 3 = 2 log 2 + 2 log 3
= 1 + 2 log 3
2 log 12 = 2 log 4 x 3 = 2 log 2^2 x 3 = 2. 2 log 2 + 2 log 3
= 2 + 2 log 3
2 log 9 = 2 log 3^2 = 2. 2log 3
Jadi 2 log 6 + 2 log 12 – 2 log 9 =
1 + 2 log 3 + 2 + 2 log 3 – 2. 2log 3
= 3
Atau
2 log 6 x 12 : 9 = 2 log 8 = 3
2) 2 log 27 = 2 log 3^3 = 3. 2log 3
3 log 8 = 3 log 2^3 = 3. 3log 2
3. 2log 3 x 3. 3 log 2
= 3 x 3 x 2log 3 x 3 log 2
= 9 x 1 = 9