mai nop cho co giao roi giup mk nha
ai giai dung mk h cho that nhieu
\(=\left(x^2+6x+9\right)-9+\left(y^2-y+\frac{1}{4}\right)-\frac{1}{4}+5\)
\(=\left(x+3\right)^2+\left(y-\frac{1}{2}\right)^2-\frac{17}{4}\)
Vì \(\left(x+3\right)^2\ge0\)
\(\left(y-\frac{1}{2}\right)^2\ge0\)
nên \(A\ge-\frac{17}{4}\)