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~5.39.217.76: r' d( l) m5 g* {5 q% I8 c, N L
7 h1 r1 c9 _7 ]+ j7 N9 Y! Y- h! \) Y5.39.217.76[ 本帖最後由 carsonchan 於 2009-2-15 04:18 PM 編輯 ] |
發表於 2009-2-15 04:12 PM
| 