Question

12£®ÎÒÃÇÒѾ­Ñ§Ï°ÁËÀûÓÃÅä·½·¨½âÒ»Ôª¶þ´Î·½³Ì£¬ÆäʵÅä·½·¨»¹ÓÐÆäËüÖØÒªÓ¦Óã®
Àý£ºÒÑÖªx¿ÉÈ¡ÈκÎʵÊý£¬ÊÔÇó¶þ´ÎÈýÏîʽ2x²-12x+14µÄÖµµÄ·¶Î§£®
½â£º2x²-12x+14=2£¨x²-6x£©+14=2£¨x²-6x+3²-3²£©+14
=2[£¨x-3£©²-9]+14=2£¨x-3£©²-18+14=2£¨x-3£©²-4£®
¡ßÎÞÂÛxÈ¡ºÎʵÊý£¬×ÜÓУ¨x-3£©²¡Ý0£¬¡à2£¨x-3£©²-4¡Ý-4£®
¼´ÎÞÂÛxÈ¡ºÎʵÊý£¬2x²-12x+14µÄÖµ×ÜÊDz»Ð¡ÓÚ-4µÄʵÊý£®
ÎÊÌ⣺ÒÑÖªx¿ÉÈ¡ÈκÎʵÊý£¬Ôò¶þ´ÎÈýÏîʽ-3x²+12x-11µÄ×îÖµÇé¿öÊÇ£¨¡¡¡¡£©

• A£® ÓÐ×î´óÖµ-1
• B£® ÓÐ×îСֵ-1
• C£® ÓÐ×î´óÖµ1
• D£® ÓÐ×îСֵ1

Answer 1

·ÖÎö ͨ¹ýÅä·½¿ÉµÃ-3x²+12x-11=-3£¨x-2£©²+1£¬¼´¿ÉÖªÆä×îÖµÇé¿ö

½â´ð ½â£º-3x²+12x-11=-3£¨x²-4x£©-11
=-3£¨x²-4x+4-4£©-11
=-3£¨x-2£©²+12-11
=-3£¨x-2£©²+1£¬
¡ßÎÞÂÛxÈ¡ºÎʵÊý£¬×ÜÓУ¨x-2£©²¡Ý0£¬
¡à-3£¨x-2£©²¡Ü0£¬
¡à-3£¨x-2£©²+1¡Ü1£¬
¼´ÎÞÂÛxÈ¡ºÎʵÊý£¬¶þ´ÎÈýÏîʽ-3x²+12x-11ÓÐ×î´óÖµ1£¬
¹ÊÑ¡£ºC£®

µãÆÀ ´ËÌ⿼²éÁËÅä·½·¨µÄÓ¦Ó㬽âÌâʱҪ¸ù¾ÝÅä·½·¨µÄ²½Öè½øÐнâ´ð£¬×¢ÒâÔÚ±äÐεĹý³ÌÖв»Òª¸Ä±äʽ×ÓµÄÖµ£®