（x-5)(x+3）＜=0(1)x-5>=0且x+3<=0即有x>=5且X<=-3,无解(2)X-5<=0且X+3>=0即有X<=5且X>=-3综上所述,解是:-3<=X<=5
（x-5)(x+3）＜=0解集为{x|-3≤x≤5}
