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第1点集合的含义以及集合之间的关系(★★★★)必做1对于任意两个正整数m,n,定义某种运算“※”如下:当m,n都为正偶数或正奇数时,m※n=m+n;当m,n中一个为正偶数,另一个为正奇数时,m※n=mn.在此定义下,集合M={(a,b)a※b=12,a∈N*,b∈N*}中的元素个数是()A.10 B.15C.16 D.18牛刀小试精妙解法当a,b同奇偶时,根据m※n=m+n将12分拆成两个同为奇数或同为偶数的和;当a,b一奇一偶时,根据m※n=mn将12分拆成一个奇数与一个偶数的积,再算其组数即可.
The meaning of the first set of points and the relationship between the collection (★ ★ ★ ★) must do 1 For any two positive integers m, n, define some kind of operation “* ” as follows: When m, n are positive even (M, n = m + n); when m, n is positive even and the other is positive odd, m * n = mn. In this definition, the set M = {(a, b) a * b = 12, a∈N *, b∈N *} is () A.10 B.15C.16 D.18 Exquisite solution of a small knife When a, b with the parity, according to m ※ n = m + n splits 12 into two equal and even numbers; when a and b are odd and even, splits 12 into an odd and an even number according to m * n = mn, Counting the number of groups can be.