求{1+0.12+0.34}*{0.12+0.34+0.56}-{1+0.12+0.34+0.56}*{0.12+0.34}的值. 提示:设1+0.21+0.34=a,0.12+0.34=b 简化计算过程注:不仅要答案,请说清楚为什么这
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![求{1+0.12+0.34}*{0.12+0.34+0.56}-{1+0.12+0.34+0.56}*{0.12+0.34}的值. 提示:设1+0.21+0.34=a,0.12+0.34=b 简化计算过程注:不仅要答案,请说清楚为什么这](/uploads/image/z/131115-3-5.jpg?t=%E6%B1%82%EF%BD%9B1%2B0.12%2B0.34%EF%BD%9D%2A%EF%BD%9B0.12%2B0.34%2B0.56%EF%BD%9D-%EF%BD%9B1%2B0.12%2B0.34%2B0.56%EF%BD%9D%2A%EF%BD%9B0.12%2B0.34%EF%BD%9D%E7%9A%84%E5%80%BC.%26%23160%3B%26%23160%3B%26%23160%3B%26%23160%3B%26%23160%3B%E6%8F%90%E7%A4%BA%EF%BC%9A%E8%AE%BE1%2B0.21%2B0.34%3Da%2C0.12%2B0.34%3Db%26%23160%3B%26%23160%3B%26%23160%3B%26%23160%3B%26%23160%3B+%E7%AE%80%E5%8C%96%E8%AE%A1%E7%AE%97%E8%BF%87%E7%A8%8B%E6%B3%A8%EF%BC%9A%E4%B8%8D%E4%BB%85%E8%A6%81%E7%AD%94%E6%A1%88%2C%E8%AF%B7%E8%AF%B4%E6%B8%85%E6%A5%9A%E4%B8%BA%E4%BB%80%E4%B9%88%E8%BF%99)
求{1+0.12+0.34}*{0.12+0.34+0.56}-{1+0.12+0.34+0.56}*{0.12+0.34}的值. 提示:设1+0.21+0.34=a,0.12+0.34=b 简化计算过程注:不仅要答案,请说清楚为什么这
求{1+0.12+0.34}*{0.12+0.34+0.56}-{1+0.12+0.34+0.56}*{0.12+0.34}的值.
提示:设1+0.21+0.34=a,0.12+0.34=b 简化计算过程
注:不仅要答案,请说清楚为什么这么做
求{1+0.12+0.34}*{0.12+0.34+0.56}-{1+0.12+0.34+0.56}*{0.12+0.34}的值. 提示:设1+0.21+0.34=a,0.12+0.34=b 简化计算过程注:不仅要答案,请说清楚为什么这
a*(b+0.56)-(a+0.56)*b
=0.56a-0.56b
=0.56*(a-b)
=0.56
这还有为什么吗 就是为了运算过程能够简化
原式=a*(b+0.56)-(a+0.56)*b=(a-b)*0.56=0.56
a=1+0.12+0.34,0.12+0.34=b
这是换元,为了简化计算
原式=a×(b+0.56)-(a+0.56)×b=ab+0.56a-ab-0.56b=0.56(a-b)=0.56×1=0.56
{1+0.12+0.34}*{0.12+0.34+0.56}-{1+0.12+0.34+0.56}*{0.12+0.34}
= a * (b +0.56)- (a+0.56)*b
=ab+0.56a - ab - 0.56b
=0.56(a-b)
=0.56
设1+0.21+0.34=a,??????????哪里有0.21?????????
如果没看错的话,你的提示:a=1+0.21+0.34 是错的,应该是a=1+0.12+0.34
将1+0.12+0.34=a,0.12+0.34=b 代入得:
a*(b+0.56)-(a+0.56)*b=ab+0.56a-ab-0.56b=0.56a-0.56b=0.56(a-b)
又因a=1+0.12+0.34 b=0.12+0.34 则a-b=1, 0.56(a...
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如果没看错的话,你的提示:a=1+0.21+0.34 是错的,应该是a=1+0.12+0.34
将1+0.12+0.34=a,0.12+0.34=b 代入得:
a*(b+0.56)-(a+0.56)*b=ab+0.56a-ab-0.56b=0.56a-0.56b=0.56(a-b)
又因a=1+0.12+0.34 b=0.12+0.34 则a-b=1, 0.56(a-b)=0.56
所以{1+0.12+0.34}*{0.12+0.34+0.56}-{1+0.12+0.34+0.56}*{0.12+0.34}=0.56
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