Question

9£®ÏÂÃæ·½³Ì×éÖУ¬½âΪ$\left\{\begin{array}{l}{x=1}\\{y=2}\end{array}\right.$µÄÊÇ£¨¡¡¡¡£©

• A£® $\left\{\begin{array}{l}{x-y=3}\\{3x-y=1}\end{array}\right.$
• B£® $\left\{\begin{array}{l}{x-y=-1}\\{3x+y=-5}\end{array}\right.$
• C£® $\left\{\begin{array}{l}{x-2y=3}\\{3x+5y=-5}\end{array}\right.$
• D£® $\left\{\begin{array}{l}{x-y=-1}\\{3x+y=5}\end{array}\right.$

Answer 1

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B¡¢°Ñ$\left\{\begin{array}{l}{x=1}\\{y=2}\end{array}\right.$´úÈë·½³Ìx-y=-1£¬×ó±ß=Óұߣ»°Ñ$\left\{\begin{array}{l}{x=1}\\{y=2}\end{array}\right.$´úÈë·½³Ì3x+y=-5£¬×ó±ß¡ÙÓұߣ»ËùÒÔ$\left\{\begin{array}{l}{x=1}\\{y=2}\end{array}\right.$²»ÊÇÔ­·½³Ì×éµÄ½â£¬¹Ê±¾Ñ¡Ïî²»·ûºÏÌâÒ⣻
C¡¢°Ñ$\left\{\begin{array}{l}{x=1}\\{y=2}\end{array}\right.$´úÈë·½³Ìx-2y=3£¬×ó±ß¡ÙÓұߣ¬ËùÒÔ$\left\{\begin{array}{l}{x=1}\\{y=2}\end{array}\right.$²»ÊÇÔ­·½³Ì×éµÄ½â£¬¹Ê±¾Ñ¡Ïî²»·ûºÏÌâÒ⣻
D¡¢°Ñ$\left\{\begin{array}{l}{x=1}\\{y=2}\end{array}\right.$´úÈë·½³Ìx-y=-1£¬×ó±ß=Óұߣ»°Ñ$\left\{\begin{array}{l}{x=1}\\{y=2}\end{array}\right.$´úÈë·½³Ì3x+y=5£¬×ó±ß=Óұߣ»ËùÒÔ$\left\{\begin{array}{l}{x=1}\\{y=2}\end{array}\right.$ÊÇÔ­·½³Ì×éµÄ½â£¬¹Ê±¾Ñ¡Ïî·ûºÏÌâÒ⣻
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