Valhalla Legends Forums Archive | Yoni's Math Forum | absolute value inequalites

AuthorMessageTime
LivedKrad
I'm having trouble following procedure for solving absolute value inequalities.

e.g. | (( x + 5 ) / 3 ) | - 3 > 6

I proceded to set the inequality up as two inequalities..

(( x + 5) / 3 ) - 3 < -6  or  (( x + 5) / 3 ) - 3 > 6

I then solved accordingly...

(( x + 5) / 3 ) < -3  or  (( x + 5) / 3 ) > 9

(x + 5) < -9  or  (x + 5) > 27

x < -14  or  x > 22

Yet, this is wrong! I can't seem to figure out what I did wrong. Help please :(
October 21, 2004, 11:05 PM
LivedKrad
UPDATE: Solved.
October 21, 2004, 11:32 PM
j0k3r
Generally when you have a problem and solve it, you post your solution so that others may learn from it.
October 22, 2004, 12:11 AM
Yoni
You can't treat the -3 with such disrespect.
First it has to blend in with the 6 in the RHS.

| (( x + 5 ) / 3 ) | > 9

Now proceed normally...
October 22, 2004, 9:59 AM

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