For any negative real number x, the value of 2x will be less than the value of 21x. Therefore, 21x cannot be the least of the five values. Thus, the least of the five values is either x−2 or 2x. When x<−2, we know that 2x−(x−2)=x+2<0. Since the difference between 2x and x−2 is negative, then 2x has the smaller value and so is the least of all five values.
Source: Omni-MATH,
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