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What does this symbol mean in math |number| ? - Marina - 11-09-2012 10:30 PM
Basically what does | | mean? For example |3x-7|=8 . Is the answer 5?
- Humbocchio - 11-09-2012 10:38 PM
I'm pretty sure it means "absolute value". It represents the number's true distance from zero, so whatever number inside the lines will be turned positive if not already so.
- Max - 11-09-2012 10:38 PM
It means absolute value so pretty much, how many spaces away from zero. So, say |7| = |-7|
It makes everything a positive
- Fgdf Dfgdfg - 11-09-2012 10:38 PM
its the sign for absolute value which means that any value which comes out of the equation is always positive, so if the answer is negative just change the - into a +
and yes 5 is the solution to this equation
- Clumsy Apple - 11-09-2012 10:38 PM
those are brackets which means you have to solve the problem in the brackets first before you do anything else. what you do is add 7 to 8 which will get you 15 then you have 3x left then you divide 15 by 3 which is 5 which you are correct.
- Antwi Daniel - 11-09-2012 10:38 PM
I I mean line
- Colin Higashi - 11-09-2012 10:38 PM
It means how far is the number from 0, so it always has 2 different answers. This problem is either 5 or -1/3.
3*5=15, 15-7=8
-1/3*3=-1, -1-7=-8
Both 8 and -8 are 8 intergers away from 0, so the answer to the absolute value of each is 8.
Basically, just change the sign of the final answer to a positive.
- Colin Higashi - 11-09-2012 10:38 PM
Yes, it's an Absolute Value, meaning that the value will always be positive. Because of this you have two answers, 5 and -1/3. (the absolute value of -8 is 8)
- jew - 11-09-2012 10:38 PM
It stands for "the absolute value of," which is the distance a number is from zero on a number line.
When solving absolute value equations, you have to account for both the positive and negative quantities.
You solve (3x-7)=8 first.
3x-7=8
3x=15
x=5
Then, solve for -(3x-7)=8
-(3x-7)=8
-3x+7=8
-3x=1
x = -1/3
So, you actually have two answers.
x=5, -1/3
- Wile E. - 11-09-2012 10:38 PM
In pre-Windows MSDOS computers, the | symbol used alone was called a pipeline and, at the time, had no place in mathematics. In Twitter, it's called a hashtag.
Used in pairs with an algebraic or numberic expression inside them, they are called absolute value symbols. Basically, the ultimate value of the expression has neither a positive nor negative value, it just has a value. Essentially, the expression itself can be positive or negative, resulting in two possible solutions. Possible because one solution may be extraneous.
To use your example,
|3x - 7| = 8
± (3x - 7) = 8
First Possible Solution:
+ (3x - 7) = 8
3x - 7 = 8
3x = 8 + 7
3x = 15
x = 15 / 3
x = 5
Second Possible Solution:
- (3x - 7) = 8
- 3x + 7 = 8
- 3x = 8 - 7
- 3x = 1
x = - 1/3
Testing Each Possible Solution,
If x = 5,
|3(5) - 7) = 8
|15 - 7|= 8
|8| = 8
If x = - 1/3,
|3(- 1/3) - 7| = 8
|- 1 - 7| = 8
|- 8| = 8
x = 5 and x = - 1/3 are both valid solutions.
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A real world application of the absolute value is in calculating the hypotenuse of a right triangle given the two sides. As you know, the hypotenuse is the square root of the sum of the squares of the sides. Normally, square rooting will return a positive/negative value, but the hypotenuse can be neither positive nor negative.
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