1) 3log(x-1) = log8 2) log(20x) - log(x-8) = 2

3log (x-1) = log 8
(×-1) log 3 = log 8
x log3-log3=log 8
x log 3=log8+log 3
× = log3 /log8+log 3
x = log3/log 3 pangkat 8
x = log3/log 30
x = 30 log3