[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!

[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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