0 bình luận về “tinh log $\frac{31-1}{9}$ -log $\frac{27}{3}$”
`~rai~`
\(\log\dfrac{31-1}{9}-\log\dfrac{27}{3}\\=\log\dfrac{10}{3}-\log9\\=\log\left(\dfrac{10}{3}:9\right)\\=\log\dfrac{10}{27}.\\\text{Áp dụng quy tắc tính logarit 1 thương:}\\\log_{a}\dfrac{b_{1}}{b_{2}}=\log_{a}b_{1}-\log_{a}b_{2}(với\quad a,b_{1},b>0;a\ne 1)\)
`~rai~`
\(\log\dfrac{31-1}{9}-\log\dfrac{27}{3}\\=\log\dfrac{10}{3}-\log9\\=\log\left(\dfrac{10}{3}:9\right)\\=\log\dfrac{10}{27}.\\\text{Áp dụng quy tắc tính logarit 1 thương:}\\\log_{a}\dfrac{b_{1}}{b_{2}}=\log_{a}b_{1}-\log_{a}b_{2}(với\quad a,b_{1},b>0;a\ne 1)\)
$\log\dfrac{31-1}{9}-\log\dfrac{27}{3}$
$=\log\dfrac{10}{3}-\log9$
$=\log\dfrac{\dfrac{10}{3}}{9}$
$=\log\dfrac{10}{27}$