(x+2)(x-3)>0
解æï¼
å½ä¸¤ä¸ªæ°aãbç¸ä¹æ¯æ´æ°æ¶ï¼aåbä¸å®æ¯åå·ï¼å³è¦ä¹é½æ¯æ´æ°ï¼a>0,b>0ï¼ï¼è¦ä¹é½æ¯è´æ°ï¼a<0,b<0ï¼ã
解ï¼
â´ (x+2)>0 ---â
(x-3ï¼>0 ---â¡
è§£å¾ x>-2å x>3
åæ¶æ»¡è¶³ä¸è¿°æ¡ä»¶çæ¯x>3
âµ (x+2)>0 ---â¢
(x-3ï¼>0 ---â£
è§£å¾ x<-2å x<3
åæ¶æ»¡è¶³ä¸è¿°æ¡ä»¶çæ¯x<-2
æ以ä¸çå¼çè§£æ¯ x<-2 æ x>3ã