Đáp án:
`1)đk:x-1>=0`
`<=>x>=1`
`2)x(x+2)>=0`
`<=>` \(\left[ \begin{array}{l}\begin{cases}x \ge 0\\x+2 \ge 0\\\end{cases}\\\begin{cases}x \le 0\\x+2 \le 0\\\end{cases}\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}\begin{cases}x \ge 0\\x \ge -2\\\end{cases}\\\begin{cases}x \le 0\\x \le -2\\\end{cases}\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}x \ge 0\\x \le -2\end{array} \right.\)
`3)-3x+2(x+2)>=0`
`<=>-3x+2x+4>=0`
`<=>4-x>=0`
`<=>x<=4`
`4)(2x-5)(3x+2)>=0`
`<=>(x-5/2)(x+2/3)>=0`
`<=>` \(\left[ \begin{array}{l}\begin{cases}x-\dfrac52 \ge 0\\x+\dfrac23 \ge 0\\\end{cases}\\\begin{cases}x-\dfrac52 \le 0\\x+\dfrac23 \le 0\\\end{cases}\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}x \ge \dfrac52\\x \le -\dfrac23\end{array} \right.\)
`5)x^2-2x+1>=0`
`<=>(x-1)^2>=0AAx in RR`
