[Powerprep Plus 1] [Inequality]
Hi guys,
Hope you are doing well. I don’t understand how ETS multiplied by (-1) and did’t flip the sign of the inequality in the second paragraph of the explanation. Could you help me understand, please?
Thank you!
Actually, they are. They start from
5 < x < 10
When multiplying by -1, they get
-5 > -x > -10
Notice that the inequalities are flipped. The last step is just rearranging the above so that we’re dealing with less than rather than greater than inequalities, which is
-10 < -x < -5
Notice that the two are the same.
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