SOLUTION: find all numbers such that three times the number is less than the number plus 18. (write answer in set notation). i can't figure out the answer. i came up with {x|x

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Question 131318: find all numbers such that three times the number is less than the number plus 18. (write answer in set notation).
i can't figure out the answer. i came up with {x|x < -9}
Found 2 solutions by stanbon, solver91311:
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
find all numbers such that three times the number is less than the number plus 18. (write answer in set notation).
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Let the number be "x".
INEQUALITY:
3x < x + 18
2x < 18
x < 9
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{x|x<9}
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Cheers,
Stan H.

Answer by solver91311(24713) (Show Source):
You can put this solution on YOUR website!
Close, but no cigar. I can't figure out where you came up with the minus sign.

A number: x
Three times the number: 3x
The number plus 18: x + 18

Three times the number is less than the number plus 18:

Add -x to both sides:

Divide both sides by 2:

{x|x < 9}

You can do a sanity check on your answer by selecting a number less than 9 and inserting it into the original inequality to see if you get a true statement, and then selecting a number larger than 9 to see if you get a false statement

True
False

SOLUTION: find all numbers such that three times the number is less than the number plus 18. (write answer in set notation). i can't figure out the answer. i came up with {x|x < -9}