A set of numbers has the property that for any number t in the set, t + 2 is in the set. If –1 is in the set, which of the following must also be in the set?
Now, about your question: we don't know which is the source integer in the set, if it's -1 than odd number less than it won't be in the set but if source integer is let's say -11 than -3 will be in the set. So -3 may or may not be in the set.
Hope it's clear.
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不懂
集合里不能有重复项，如果t=-3,则t+2=-1由于题目中说集合中有-1所以t不能取-3
Now, about your question: we don't know which is the source integer in the set, if it's -1 than odd number less than it won't be in the set but if source integer is let's say -11 than -3 will be in the set. So -3 may or may not be in the set.
Hope it's clear.
t+2=-1不可以吗
为什么不能往前推
对数集任意t,有t+2在数集当中。从-1属于这个SET可以推出1、3、5、7……但是不能向前推，即不能说明对于任意 ...
为什么不能向前推呢？求解答。
你向前推的话就相当于假设了对任意数t，有t-2在数集中，而题目中没有。