请尽量给出详述,本人数学不好.The diagonal of the floor of a rectangular closet is 15/2 feet.The shorter side of the closet is 17/4 feet.What is the area of the closet in the square feet?这题我想的是(15/2)平方-(17/4)平方
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请尽量给出详述,本人数学不好.The diagonal of the floor of a rectangular closet is 15/2 feet.The shorter side of the closet is 17/4 feet.What is the area of the closet in the square feet?这题我想的是(15/2)平方-(17/4)平方
请尽量给出详述,本人数学不好.
The diagonal of the floor of a rectangular closet is 15/2 feet.The shorter side of the closet is 17/4 feet.What is the area of the closet in the square feet?
这题我想的是(15/2)平方-(17/4)平方然后开方,再乘17/4.可是答案并不是这个.
How many 3-digit positive integers are odd and do not contain the digit "5"
请尽量给出详述,本人数学不好.The diagonal of the floor of a rectangular closet is 15/2 feet.The shorter side of the closet is 17/4 feet.What is the area of the closet in the square feet?这题我想的是(15/2)平方-(17/4)平方
第一题我也是这么个思路.
第二题:按位数算.百位可取除5之外1~9,即8种可能.十位1~9,9种可能.个位满足奇数且不含5的,有1,3,7,9,4种可能.所以共有8*9*4=282个数.
三位正整数是奇数但不包括数字5的有多少个?
见http://zhidao.baidu.com/link?url=JNz3Hy8jlYm_dJqf-8iycvJaGVPlcopZ_XGmQS0gOfvVcojc555puAZFB57VaAko-55l7dXpKOG_GF28VW9Qgq
前面那个题做法没错,用勾股定理求出另一边,再求面积