Re: [計量] 請教一題計量
※ 引述《joannepu1110 (花花兒)》之銘言：
: If the value of the expresiion above is to be halved by doubling exactly one
: of the five numbers a,b,c,d,or e, which should be doubled??
: a+ b/c / d/e
: 式子是這樣= =" 希望有人看的懂
: 是在B book 第177頁 第20題
: 答案是d 要乘以double
: 麻煩各位了!!!
(a + b/c) / (d/e) = ( (ac + b)/c ) / (d/e)
= (ace + be) / (cd) ------------(1)
Target: doubling a,b,c,d,or e to make (1) halved.
So, either "c" or "d" has to be doubled.
If we doubled "c", the term (ace + be) will also be influenced,
resulting in the failure of halving (1).
Hence, "d" is the only choice which can be doubled to cause (1) halved.
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A l c O H o L i c
David
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