\(x+\left(\frac{-31}{12}\right)^2\left(\frac{49}{12}\right)^2-x=y\)
\(x+\frac{961}{144}.\frac{2401}{144}-x=y\)
\(x+\frac{2307361}{20736}-x=y\)
\(y=\frac{2307361}{20736}\)
Thay vào \(x+\frac{961}{144}.\frac{2401}{144}-x=y\) ta được
\(x+\frac{2307361}{20736}-x=y\)
\(x-x+\frac{2307361}{20736}=\frac{2307361}{20736}\)
Vậy x thuộc N;\(y=\frac{2307361}{20736}\)
\(\Leftrightarrow\left(x-x\right)+\frac{961}{144}\cdot\frac{2401}{144}=y\Leftrightarrow y=\frac{2307361}{20736}\)
\(\Rightarrow x\in R\)
( hình như đề sai :v )