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View Full Version : Number line am I correct


mix786
Oct 1, 2007, 07:29 AM
OK My question is :
Graph on the number line:
-|x| - 2>-5; = [Integers]
so I did:
-|x| - 2 > -5
subtract 2 from both sides
-|x| > -7
|x| > 7
x > 7 or x < -7
CORRECT
I can't seem to make the number line so I will just tell you verbally
put a dot on -7 on the number line and make an arrow going left
put a dot on 7 on the number line and make an arrow going right

albear
Oct 1, 2007, 07:45 AM
when you say subtract 2 from both sides you should have ended up with
-x-4>-7

in otherwords I would think that you would add 2 to both sides getting
-x>-3

mix786
Oct 1, 2007, 07:52 AM
Ok I see
so than it has to be
x > 3 or x < -3

albear
Oct 1, 2007, 07:55 AM
I don't see a squared in there unles there's something that your not telling us or I'm missing the point why there are 2 solutions

iagree with the x>3

asterisk_man
Oct 1, 2007, 08:09 AM
-\left|x\right| - 2>-5 \\
\text{add 2 to both sides} \\
-\left|x\right|>-3\\
\text{multiply both sides by -1 and don't forget to flip the > to a <} \\
\left|x\right|<3 \\
\text{expand the absolute value} \\
-3<x<3


To draw it on the number line put an open dot on -3 and 3 with a line between them.

Makes sense??

Clearly x>3 is wrong. Try 4. -|4|-2>-5? No, -6!>-5.

albear
Oct 1, 2007, 08:10 AM
Asterisk man saves the day again

mix786
Oct 1, 2007, 08:15 AM
Thanks both of you for making me understand.