Ta có:
\(x=0,818181...=0,\left(81\right)=\frac{81}{99}=\frac{9}{11}\)
\(y=1,222222...=1,\left(2\right)=1+0,\left(2\right)=1+\frac{2}{9}=\frac{11}{9}\)
\(\Rightarrow x.y=\frac{9}{11}.\frac{11}{9}=1\)
Vậy x.y = 1
Ta có :
\(x=0,\left(81\right)=\frac{81}{99}=\frac{9}{11}\)
\(y=1,\left(2\right)=1+\frac{2}{9}=\frac{11}{9}\)
\(\Rightarrow x=\frac{1}{y}\Rightarrow xy=1\)
Vậy ...
\(x=0,818181=0,\left(81\right)=\frac{9}{11}\)
\(y=1,222222=1,\left(2\right)=\frac{11}{99}\)
\(\Rightarrow x.y=\frac{9}{11}.\frac{11}{9}=1\)