※ 引述《NightCat427 (寵愛，盡在不言中)》之銘言： : 1.For every positive even integer n, the function h(n) is defined to be the : product of all the even integers from 2 to n, inclusive. If p is the smallest : prime factor of h(100)+1, then p is : A.between 2 and 10 : B.between 10 and 20 : C.between 20 and 30 : D.between 30 and 40 : E.greater than 40 : 答案 E : 2.If x, y, and z are integers and xy+z is an odd integer, is x an even integer? : (1) xy+xz is an even integer : (2) y+xz is an odd integer : 答案 A 1.你可以先變成 (2^50(50!)+1)/p 可以看出來2^50(50!)的質因數2 3 5 7...47 但是他又加一個1所以47以下的質因數都不能整除(2^50(50!)+1) 因此最小的質因數一定是大於47 2.我不確定 我是把(xy+xz)-(xy+z)=z(x-1) even-odd --->odd 所以x-1是odd 所以x是even 利用二好像得不到什麼結果 --

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