12. 25 log 81 = 5^2 log 3^4 4/2 5 log 3 2 5 log 3 nb : 3 log 5 = p , berarti 5 log 3 = 1/p Jadi 2 5 log 3 = 2 1/p = 2/p 13. a log b - b log a = a log a^4 - a^4 log a = 4 a log a - 1/4 a log a nb : a log a = 1 jadi : 4 a log a - 1/4 a log a = 4 . 1 - 1/4 .1 = 4 - 1/4 = 3 3/4
2 log 3^2 + 2 log 5
2 2 log 3 + 2 log 5
2 log 3 = p , 2 log 5 = q
berarti 2 2log 3 + 2 log 5 = 2p +q
12. 25 log 81 = 5^2 log 3^4
4/2 5 log 3
2 5 log 3
nb : 3 log 5 = p , berarti 5 log 3 = 1/p
Jadi 2 5 log 3 = 2 1/p
= 2/p
13. a log b - b log a = a log a^4 - a^4 log a
= 4 a log a - 1/4 a log a
nb : a log a = 1
jadi : 4 a log a - 1/4 a log a = 4 . 1 - 1/4 .1
= 4 - 1/4
= 3 3/4