[計量] 一題數學

看板GRE作者 (c8 8c )時間16年前 (2008/06/03 00:42), 編輯推噓1(105)
留言6則, 3人參與, 最新討論串3/11 (看更多)
那呈我剛剛問的觀念~ If Sam were twice as old as he is, he would be 40 years older than Jim. If Jim is 10 years younger than Sam, how old is Sam? 我的算法是 2sam = he he = J +40 J = S-10 解聯立~ 可是這跟之前版友的回答就抵觸了 依版友的回答應該是sam = 2he 吧 我時在不知道我的盲點在哪= = 麻煩各位板友了~謝謝~ -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 122.120.112.208

06/03 00:46, , 1F
答案是30忘了說~
06/03 00:46, 1F

06/03 01:03, , 2F
Sam x 2 = Jim + 40; Sam = Jim + 10;
06/03 01:03, 2F

06/03 01:03, , 3F
二元一次聯立方程式
06/03 01:03, 3F

06/03 01:14, , 4F
2Sam - 40 = Sam -10 式子兩邊皆為Jim
06/03 01:14, 4F

06/03 01:32, , 5F
twice as old as he is:他實際年齡的2倍
06/03 01:32, 5F

06/03 01:39, , 6F
感謝樓上的版友~我知道我錯在哪了~
06/03 01:39, 6F
文章代碼(AID): #18H2Bnns (GRE)
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文章代碼(AID): #18H2Bnns (GRE)