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When they ask you about ONE number, whether it satisfy the given inequality or not,
the simplest way to answer this question is to substitute the given number into the inequality,
calculate each side and compare, if the inequality is true.
But if they ask you about 10, or 20, or 100 given numbers, then the better way is to solve this inequality
and to determine its solution set, and then to find out for each given number if it is in the solution set or not.
Doing this way, you will save your time and efforts.