Bài 3: 

b: \(B_1=-\left|2x-3\right|+2\le2\forall x\)

Dấu '=' xảy ra khi \(x=\dfrac{3}{2}\)

\(B_2=-\left|x+4\right|+5\le5\forall x\)

Dấu '=' xảy ra khi x=-4

Bài 3:

b) Xét số \(-B_3=6+\left|x+4\right|\ge6\Rightarrow B_3\le-6\)

Dấu '=' xảy ra \(\Leftrightarrow x=-4\)

\(3,\\ b,B_1=2-\left|3-2x\right|\le2\)

Dấu \("="\Leftrightarrow x=\dfrac{3}{2}\)

\(B_2=5-\left|x+4\right|\le5\)

Dấu \("="\Leftrightarrow x=-4\)

\(B_3=-6-\left|x+4\right|\le-6\)

Dấu \("="\Leftrightarrow x=-4\)

\(c,15-\left(x^2-4\right)^2-\left|x+2\right|\le15\)

Dấu \("="\Leftrightarrow\left\{{}\begin{matrix}x^2-4=0\\x+2=0\end{matrix}\right.\Leftrightarrow x=-2\)

\(C_2=10-\left|2x-1\right|-\left|y+x\right|\le10\)

Dấu \("="\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{1}{2}\\y=-x\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{1}{2}\\y=-\dfrac{1}{2}\end{matrix}\right.\)

1 Yes, it can

2 It can cause heal problems such as eye-tiredness and obesity

3 No, I won't

4 We should use it for a limited time

1. On the ocean 

2. Yes

3. do house work , cleaning the floor , cooking meals , washing clothes , feeding his pets .

Bài 4: 

Nhóm 1: x;1/3x; 8x

Nhóm 2: \(x^2;5x^2;-3x^2\)

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