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If the inequality has the same number on both sides for the answer is that ok?

If the inequality has the same number on both sides for the answer is that ok?-example-1
User Joseph Lam
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1 Answer

6 votes
If the problem was |6y+6| < 0, then you would be able to say 0 < 6y+6 < 0 (because of the template below)

Template:
if |x| < k, then -k < x < k

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However, the inequality sign is not a "less than" sign. Instead its a "greater than" sign.

So instead you should use this template

if |x| > k then x > k or x < -k

So if
|6y+6| > 0
then
6y+6 > 0 or 6y+6 < 0

Solve each inequality for y
6y+6 > 0
6y+6-6 > 0-6 ... subtract 6 from both sides
6y > -6
6y/6 > -6/6 ... divide both sides by 6
y > -1

Do the same for the other inequality
6y+6 < 0
6y+6-6 < -6
6y < -6
6y/6 < -6/6
y < -1

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So overall, the two solutions are y > -1 or y < -1

The keyword "or" is important. You can only choose one inequality or the other, but not both.

User Guillaume Smet
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