SOLUTION: |-3x-5|>=2 The answer should have form b < x < c or the form x < b or x > c Is all my paper says to do. I dont understand HOW they want me to put it in that form and do the p

Algebra ->  Absolute-value -> SOLUTION: |-3x-5|>=2 The answer should have form b < x < c or the form x < b or x > c Is all my paper says to do. I dont understand HOW they want me to put it in that form and do the p      Log On


   



Question 150360: |-3x-5|>=2
The answer should have form b < x < c
or the form x < b or x > c
Is all my paper says to do.
I dont understand HOW they want me to put it in that form and do the problem.
The topic on the paper says, Absolute Value Inequalities.
I would greatly appreciate it if someone coul dhelp me figur eout how to do this, and show me how they had done it so i can learn how to do it myself.
Thanks,
KKG.

Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
 

%28-3x-5%29%3E=2

--------------------------------------------
Learn rules for removing absolute values from
inequalities of these forms:


Rule 1:
-------------------------------------------
      
abs%28EXPRESSION%29%3CN, abs%28EXPRESSION%29%3C=N (where N is not negative)

Write as 

-N+%3C+EXPRESSION+%3C+N, -N+%3C=+EXPRESSION+%3C=+N, respectively.

then solve. [If N is negative, there is no solution,
and solution set = Ø)


------------------------------------------------------
------------------------------------------------------

Rule 2:
-------------------------------------------
abs%28EXPRESSION%29%3EN, abs%28EXPRESSION%29%3E=N (where N is not negative)

Write as 

EXPRESSION+%3C+-NOREXPRESSION+%3E+N, EXPRESSION+%3C=+-NOREXPRESSION+%3E=+N
respectively.

Then solve each part.  (If N is negative, solution set is 
"all real numbers".)
------------------------------------------

You need Rule 2.  I gave you Rule 1 also because you
will need it for other problems:

abs%28-3x-5%29%3E=2

EXPRESSION+=+-3x-5

N=2

So write:

-3x-5+%3C=+-2OR-3x-5+%3E=+2

Solve each part:

Add 5 to both sides of both parts:

-3x+%3C=+3OR-3x+%3E=+7

Divide both sides of both parts by -3,
Notice that dividing an inequality by a NEGATIVE
NUMBER reverses the inequality sign:

%28-3x%29%2F%28-3%29+%3E=+3%2F%28-3%29OR%28-3x%29%2F%28-3%29+%3C=+7%2F3

x+%3E=+-1ORx+%3C=+-7%2F3

So we shade the number line:

1. to the right of -1
and
2. to the left of -7%2F3, which is the same as -21%2F3.


<=======@-----------@==================>
 -3       -2       -1        0        1            

The circles should be darkened since the inequalities
are all underlined:

Solution in interval notation is 

(-infinity,-7%2F3] U [-1,infinity)

Edwin