ya ... right answer is 公仔箱論壇7 @* Q" M5 x& O# Q" g2 _
a)$60-$55=賺左$5公仔箱論壇2 ?" Y; S( i9 ~: A1 y& [' F/ b
公仔箱論壇" i, A. i' ^ h0 K. z0 P' c
b)$60-$62=花多左$2公仔箱論壇7 m, a1 p6 b5 `# i
. m. V. V9 J' u8 e; s# l
c)$68-$62=賺左$6 ( s, ?0 R: T- r5 R - @, n: w$ n+ R, j# g5 Q- p# f公仔箱論壇所以:$5-$2+$6=$9