Đáp án:

Giải thích các bước giải:

 $\dfrac{-1}{10}$ . $\dfrac{1}{100}$ .$\dfrac{1}{1000}$ .$\dfrac{1}{10000}$ .$\dfrac{1}{100000}$ 

= $\dfrac{-1}{10^1}$ .$\dfrac{1}{10^2}$ .$\dfrac{1}{10^3}$ .$\dfrac{-1}{10^4}$ .$\dfrac{-1}{10^5}$

= $\dfrac{-1}{10^1.10^2.10^3.10^4.10^5}$ = $\dfrac{-1}{10^(1+2+3+4+5)}$ = $\dfrac{-1}{10^(15)}$

= $\dfrac{-1}{10^(15)}$ 

= $\dfrac{-1}{1000000000000000}$