1. = log_3(6*3/2)=log_3(9)=2
2. =log_2(15/(15/16))=log_2(16)=4
3. =log_12(144^(1/3))=log_12((12^2)^(1/3))=log_12(12^(2/3))=2/3
4. =log_5(sqrt(49))=log_5(7)
5. =log_7(8)-log_7(24)=log_7(1/3)
6. =log_1/2(81)-log_1/2(9)-log_1/2(36)=log_1/2(1/4)=2
7. =log_2(68)-log_2(17)=log_2(4)=2