\(E=2x^2+3x+4=2\left(x^2+\dfrac{3}{2}x+2\right)=2\left(x^2+2.x.\dfrac{3}{4}+\dfrac{9}{16}+\dfrac{23}{16}\right)=2\left(x+\dfrac{3}{4}\right)^2+\dfrac{23}{8}\ge\dfrac{23}{8}\forall x\)Vậy: \(Min_E=\dfrac{23}{8}\Leftrightarrow x=-\dfrac{3}{4}\)
\(F=x^2-2x+y^2-4y+7=\left(x^2-2x+1\right)+\left(y^2-4y+4\right)+2=\left(x-1\right)^2+\left(y-2\right)^2+2\ge2\forall x;y\)
Vậy: \(Min_F=2\Leftrightarrow x=1\&y=2\)
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