1: \(Q=x^2+100x+2500-1500\)
\(=\left(x+50\right)^2-1500>=-1500\)
Dấu '=' xảy ra khi x=-50
2: \(=a^2+2\cdot a\cdot\dfrac{3}{2}+\dfrac{9}{4}+\dfrac{7}{4}=\left(a+\dfrac{3}{2}\right)^2+\dfrac{7}{4}>=\dfrac{7}{4}\)
Dấu '=' xảy ra khi a=-3/2
3: \(=-\left(x^2-2x+1-1\right)=-\left(x-1\right)^2+1< =1\)
Dấu '=' xảy ra khi x=1