【GRE数学】If x is an odd integer,for which of the following equation_英语解答

【GRE数学】If x is an odd integer,for which of the following equations must y be an even integer?
RT 其他选项都排除了,只剩x+2y=7 & 2x+y=6
PS.by the way,integers between 1 and 100,包括1和100这两个数吗?

人气：268 ℃　时间：2020-01-27 23:58:15

解答

2x+y=6中y是偶数.因为2x是偶数,因此y只能是偶数,而第一个式子中y不论奇数或偶数,那个式子都有成立的可能.
integers between 1 and 100,应该是包括1和100的.嗯明白了