Giúp câu 10, câu 11 ạ

Đáp án:

`10)`

`a)` `log_(3)45+log_(3)``1/5`

`=log_(3)(45.(1)/5)`

`=log_(3)9`

`=log_(3)3^2=2`

`b)` `log_(4)48-log_(4)3`

`=log_(4)``(48/3)`

`=log_(4)``16`

`=log_(4)``4^2=2`

`c)` `log_2``16/3+2log_(2)sqrt6`

`=log_2``16/3+log_(2)(sqrt6)^2`

`=log_2``16/3+log_(2)6`

`=log_2``(16/(3).6)`

`=log_2``32`

`=log_2``2^5=5`

`d)` `1/3log_3``9/7+log_(3)root(3)(7)`

`=1/3log_3``9/7+log_(3)7^(1/3)`

`=1/3log_3``9/7+1/3log_(3)7`

`=1/3log_3``(9/(7).7)`

`=1/3log_3``9`

`=1/3log_3``3^2`

`=1/(3).2=2/3`

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`11)`

`a)` `3^(log_(3)5)=5`

`b)` `e^ln3=e^(log_(e)3)=3`

`c)` `7^(2log_(7)8)=(7^(log_(7)8))^2=8^2=64`

`d)` `2^(log_(2)3+log_(2)5)=2^(log_(2)(3.5))=2^(log_(2)15)=15`

`e)` `4^(\log_2 1/5)=(2^2)^(\log_2 1/5)=(2^(\log_2 1/5))^2=(1/5)^2=1/25`

`g)` `0,001^log2=(10^-3)^log2=(10^log2)^(-3)=2^(-3)=1/8`