推 s035280236 : 請問第一行是什麼意思啊 02/13 22:49
※ 引述《s035280236 (安安)》之銘言：
: https://i.imgur.com/84GJyRp.jpg
: 如題
: 這題該怎麼解qq
: 感謝各位
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: Sent from JPTT on my Xiaomi Redmi Note 4.
BF/10 * 2/1 * DE/DF = 1
=> DF/BF = DE/5
8 : 6 = 2DE : 10
=> DE = 80/12 = 20/3
CD = 32/3
=> DF/BF = 4/3
1/1 * AF/BF * 6/(32/3) = 1
=> AF/BF = 16/9
=> DF/AF = 4/3 * 9/16 = 3/4
選(C)
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