SOLUTION: Hi, I was wondering if you could please help me with an absolute value question please? I did the math and got -5 and 5 and it is an "or" line but they both equal the equation. The

Algebra ->  Absolute-value -> SOLUTION: Hi, I was wondering if you could please help me with an absolute value question please? I did the math and got -5 and 5 and it is an "or" line but they both equal the equation. The      Log On


   



Question 892208: Hi, I was wondering if you could please help me with an absolute value question please? I did the math and got -5 and 5 and it is an "or" line but they both equal the equation. The problem is |3x| > 15. I did this:
3x>15 Or 3x>-15
3x/3> 15/3 3x/3>-15/3
x>5 x> -5
The problem is that they both equal 15 & the problem is >15

Found 3 solutions by josgarithmetic, lwsshak3, MathTherapy:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
abs%283x%29%3E-15

3abs%28x%29%3E-15
abs%28x%29%3E-15%2F3
abs%28x%29%3E-5

An absolute value will always be positive or zero; never negative.

IF x%3E=0 THEN
x%3E-5.

IF x%3C0 THEN
-x%3E-5
x%3C5-----multiplied by -1 on both sides must cause reversal of inequality direction

Draw a number line and label with -5, 0, and 5, so you can see clearly. Graph x%3E-5 and x%3C5. You will see that the solution which satisfies BOTH conditions is highlight%28-5%3Cx%3C5%29 or, the open interval between -5 and +5.

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
|3x| > 15
2 cases:
..
3x>15
x>5
..
-3x>15
3x<-15
x<-5
solution:
x>5 or x<-5

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

Hi, I was wondering if you could please help me with an absolute value question please? I did the math and got -5 and 5 and it is an "or" line but they both equal the equation. The problem is |3x| > 15. I did this:
3x>15 Or 3x>-15
3x/3> 15/3 3x/3>-15/3
x>5 x> -5
The problem is that they both equal 15 & the problem is >15

|3x| > 15
Thus, 3x > 15 OR 3x < - 15
You should get: highlight_green%28x+%3E+5%29 OR highlight_green%28x+%3C+-+5%29