SOLUTION: 6x-3 divided by 3 in absolute value greater or equal to 7 dont know how to tell which method to use the or method or other
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Question 715875: 6x-3 divided by 3 in absolute value greater or equal to 7 dont know how to tell which method to use the or method or other Answer by Edwin McCravy(20081) (Show Source):
≧ 7
Simplify by factoring out 3 in the numerator:
≧ 7
Then cancel the 3's
≧ 7
|2x - 1| ≧ 7
There are four rules for removing absolute value bars in
absolute value inequalities:
If A is positive:
1. |EXPRESSION| < A becomes
-A < EXPRESSION < A
2. |EXPRESSION| ≦ A becomes
-A ≦ EXPRESSION ≦ A
3. |EXPRESSION| > A becomes
EXPRESSION < -A OR EXPRESSION > A
4. |EXPRESSION| ≧ A becomes
EXPRESSION ≦ -A OR EXPRESSION ≧ A
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|2x - 1| ≧ 7
is rule 4 above where EXPRESSION = 2x - 1 and A = 7
|2x - 1| ≧ 7 becomes
2x - 1 ≦ -7 OR 2x - 1 ≧ 7
Solve each for x:
2x ≦ -6 OR 2x ≧ 8
Divide through by 2
x ≦ -3 OR x ≧ 4
Draw the graph on a number line:
<=========●--------------------●===========>
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8
Then the interval notation for this is an abbreviation
for the above graph:
(-∞,-3] U [4,∞)
Edwin