Question 53877: Solve absolute value inequality and graph solution set.
1 > 1/2|6 - x| - 3/4 Found 2 solutions by stanbon, AnlytcPhil:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Solve absolute value inequality and graph solution set.
1>1/2{6-x}-3/4
Add 3/4 to both sides to get:
(1/2)|6-x|< 7/4
Divide both sides by 1/2 to get:
|6-x|<7/2
-7/2< 6-x <7/2
Subtract 6 along the line to get:
-19/2 < -x < -5/2
Multiply thru by -1 to get:
5/2 < x < 19/2
Graph this on a number line with open circles at the end points.
Cheers,
Stan H.
Solve absolute value inequality and graph solution set.
1>1/2|6-x|-3/4
1 3
1 > ---|6 - x| - ---
2 4
Write the 1 as 1/1 so every term will have a fraction:
1 1 3
--- > ---|6 - x| - ---
1 2 4
The LCD = 4 so multiply every term by 4 written as 4/1.
That is put
4
---·
1
In front of every term:
4 1 4 1 4 3
---·--- > ---·---|6 - x| - ---·---
1 1 1 2 1 4
Now cancel the 2 into the 4 and the 4 into the 4
2 1
4 1 4 1 4 3
---·--- > ---·---|6 - x| - ---·---
1 1 1 2 1 4
1 1
And all you have left is
4 > 2|6 - x| - 3
Isolate the term with the absolute value:
Add 3 to both sides:
7 > 2|6 - x|
Solve for the absolute value
7
--- > |6 - x|
2
It's easier to see if the absolute value is on
the left. So we can write the above as
7
|6 - x| < ---
2
The absolute value of 6 - x will be less than 7/2
if and only if 6 - x is between -7/2 and +7/2.
That is:
7 7
- --- < 6 - x < ---
2 2
Clear of fractions by multiplying all three sides
by 2
-7 < 12 - 2x < 7
Add -12 to all three sides
-19 < -2x < -5
Divide all three sides by -2, remembering to reverse
the inequalities when dividing by a negative number.
19/2 > x > 5/2
It is easier to see this is we write this inequality
smallest to largest:
5/2 < x < 19/2
2.5 < x < 9.5
The graph:
--------------o===========================o---
-1 0 1 2 3 4 5 6 7 8 9 10
In interval notation the solution is (5/2, 19/2)
Edwin