cost 15 to make the shoes, gave the boy 29 for change, and need 29 more to pay back the nieghborhood, so 15+29+29= 73. simple ,math problem. much easier than calculus~7 c2 m" |7 B" i$ t3 _3 b5 h# y
tvb now,tvbnow,bttvb- B4 ^: u7 x7 f+ p
[ 本帖最後由 carsonchan 於 2009-2-15 04:18 PM 編輯 ] |