Câu hỏi:

\(\left\{ a;b;c \right\}\)

\(\left\{ a;b \right\}\)

\(\left\{ c \right\}\)

\(\left\{ a;b;c;d \right\}\)

\(M=\left( -\infty ;9 \right]\)

\(M=\left( -\infty ;9 \right)\)

\(M=\left( 9;+\infty \right)\)

\(M=\left[ -\infty ;9 \right)]\)

\(b=-8\)

\(b=16\)

\(b=8\)

\(b=-16\)

\(-\frac{2}{3}\)

\(\frac{1}{2}\)

\(\frac{2}{3}\)

\(\frac{1}{3}\)

\(\left( 1;-\frac{1}{2} \right)\in S\)

\(\left( -1;-1 \right)\in S\)

\(\left( -\frac{1}{2};\frac{2}{5} \right)\in S\)

\(\left( 1;1 \right)\in S\)

\(\bar{Q}\) : “\(\exists x\in \mathbb{R},\,{{x}^{2}}-1<0\)”

\(\bar{Q}\) : “\(\exists x\in \mathbb{R},\,{{x}^{2}}-1\le 0\)”

\(\bar{Q}\) : “\(\exists x\in \mathbb{R},\,{{x}^{2}}-1\ge 0\)”

\(\bar{Q}\) : “\(\forall x\in \mathbb{R},\,{{x}^{2}}-1>0\)”

\(\left\{ x\in \mathbb{Q}\,|\,{{x}^{2}}-4x+2=0 \right\}\)

\(\left\{ x\in \mathbb{R}\,|\,{{x}^{2}}-4x+3=0 \right\}\)

\(\left\{ x\in \mathbb{Z}\,|\,\left| x \right|<1 \right\}\)

\(\left\{ x\in \mathbb{Z}\,|\,6{{x}^{2}}-7x+1=0 \right\}\)

1

2

3

4

\(S=6\sqrt{3}.\)

\(S=24\)

\(S=18\sqrt{3}.\)

\(S=12\sqrt{3}.\)

\({{150}^{\circ }}\)

\({{135}^{\circ }}\)

\({{105}^{\circ }}.\)

\({{120}^{\circ }}\)