Question

13£®Ä³É̵êÓõ÷µÍ¼Û¸ñµÄ·½Ê½´ÙÏún¸ö²»Í¬µÄÍæ¾ß£¬µ÷ÕûºóµÄµ¥¼Ûy£¨Ôª£©Óëµ÷ÕûÇ°µÄµ¥¼Ûx£¨Ôª£©Âú×ãÒ»´Îº¯Êý¹Øϵ£¬Èç±í£º

	µÚ1¸ö	µÚ2¸ö	µÚ3¸ö	µÚ4¸ö	¡­	µÚn¸ö
µ÷ÕûÇ°µÄµ¥¼Ûx£¨Ôª£©	x1	x2=12	x3=48	x4	¡­	xn
µ÷ÕûºóµÄµ¥¼Ûy£¨Ôª£©	y1	y2=9	y3=39	y4	¡­	yn

ÒÑÖªÕân¸öÍæ¾ßµ÷ÕûºóµÄµ¥¼Û¶¼´óÓÚ2Ôª£®
£¨1£©ÇóyÓëxµÄº¯Êý¹Øϵʽ£¬²¢È·¶¨xµÄÈ¡Öµ·¶Î§£»
£¨2£©Ä³¸öÍæ¾ßµ÷ÕûÇ°µ¥¼ÛÊÇ120Ôª£¬¹Ë¿Í¹ºÂòÕâ¸öÍæ¾ßÊ¡Á˶àÉÙÇ®£¿

Answer 1

·ÖÎö £¨1£©Éèy=kx+b£¬¸ù¾ÝÌâÒâÁз½³Ì×é¼´¿ÉµÃµ½½áÂÛ£¬ÔÙ¸ù¾ÝÒÑÖªÌõ¼þµÃµ½²»µÈʽÓÚÊǵõ½xµÄÈ¡Öµ·¶Î§ÊÇx£¾$\frac{18}{5}$£»
£¨2£©½«x=120´úÈëy=$\frac{5}{6}$x-1¼´¿ÉµÃµ½½áÂÛ£»

½â´ð ½â£º£¨1£©Éèy=kx+b£¬ÓÉÌâÒâµÃx=12£¬y=9£¬x=48£¬y=39£¬
¡à$\left\{\begin{array}{l}{9=12k+b}\\{39=72k+b}\end{array}\right.$
½âµÃ$\left\{\begin{array}{l}{k=\frac{5}{6}}\\{b=-1}\end{array}\right.$£¬
¡àyÓëxµÄº¯Êý¹ØϵʽΪy=$\frac{5}{6}$x-1£¬
¡ßÕân¸öÍæ¾ßµ÷ÕûºóµÄµ¥¼Û¶¼´óÓÚ2Ôª£¬
¡à$\frac{5}{6}$x-1£¾2£¬½âµÃx£¾$\frac{18}{5}$£¬
¡àxµÄÈ¡Öµ·¶Î§ÊÇx£¾$\frac{18}{5}$£»

£¨2£©½«x=120´úÈëy=$\frac{5}{6}$x-1µÃy=$\frac{5}{6}$¡Á120-1=99£¬
120-99=21£¬
´ð£º¹Ë¿Í¹ºÂòÕâ¸öÍæ¾ßÊ¡ÁË21Ôª£»

µãÆÀ ±¾Ì⿼²éÁËÒ»´Îº¯ÊýµÄÓ¦Óã¬Çóº¯ÊýµÄ½âÎöʽ£¬Êì¼ÇÒ»´Îº¯ÊýµÄÐÔÖÊÊǽâÌâµÄ¹Ø¼ü£®