Tham khảo
Xét `(\frac{9}{11}-0,81)^{2003}=(\frac{9}{1100})^{2003}(1)`
Xét `(\frac{9}{11})^{2003}×\frac{1}{10^{4006}}=(\frac{9}{11}×\frac{1}{100})^{2003}=(\frac{9}{1100})^{2003}(2)`
Từ `(1)(2)⇒(\frac{9}{11}-0,81)^{2003}=(\frac{9}{11})^{2003}×\frac{1}{10^{4006}}`
Vì cùng bằng `(\frac{9}{1100})^{2003}`