1, Ta có: \(\left(x-y\right)^6+|47-x|+3^3\ge0+0+9=9\)
Dấu "=" xảy ra khi \(\hept{\begin{cases}x-y=0\\47-x=0\end{cases}\Leftrightarrow}\hept{\begin{cases}x=47\\y=47\end{cases}}\)
2, Ta có: \(\left(x+5\right)^2+\left(y-9\right)^2+2020\ge0+0+2020=2020\)
Dấu "'=" xảy ra khi \(\hept{\begin{cases}x+5=0\\y-9=0\end{cases}\Leftrightarrow\hept{\begin{cases}x=-5\\y=9\end{cases}}}\)