1.(x+3)(x-1)≤0,解集是{x|-3≤x≤1}
2.(2x+1)^2≥0,解集是R
3.(x+2)(x-3)≥0,解集是{x|x≤-2或x≥3}
4.(x-3)^2≤0,解集是{3}
5.x^2-x-4>0,解集是{x|x<(1-√17)/2或x>(1+√17)/2}
6.解集是Φ