What are the solutions to this absolute value equation?

In summary, the conversation is about solving the equation |1/2x+1|=|x| and the correct answers for x given are 2 and -2/3. There is a correction made to one of the solutions and a clarification about the interpretation of the notation 1/2x. It is recommended to use bracketing symbols or $\LaTeX$ to avoid confusion when writing equations.
  • #1
Alexstrasuz1
20
0
I have trouble solving this equation
|1/2x+1|=|x|

My answers are x=2 and x=-2/3
 
Last edited:
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  • #2
corrected mistake in (2) as pointed out by MarkFL in the successive post...

Alexstrasuz said:
I have trouble solving this equation
|1/2x+1|=|x|

My answers are x=2 and x=-2/3

An easy way is to find the solution of the equations...

$\displaystyle \frac{1}{2 x} + 1 = x \implies 2\ x^{2} - 2\ x - 1 =0 \implies x = \frac{1 \pm \sqrt{3}}{2}\ (1)$

$\displaystyle \frac{1}{2 x} + 1 = - x \implies 2\ x^{2} + 2\ x + 1 =0 \implies x = \frac{- 1 \pm i}{2}\ (2)$

Kind regards

$\chi$ $\sigma$

P.S. MarlFL has 'discovered' a mistake in (2) and I corrected it... sorry!...
 
Last edited:
  • #3
chisigma said:
An easy way is to find the solution of the equations...

$\displaystyle \frac{1}{2 x} + 1 = x \implies 2\ x^{2} - 2\ x - 1 =0 \implies x = \frac{1 \pm \sqrt{3}}{2}\ (1)$

$\displaystyle \frac{1}{2 x} + 1 = - x \implies 2\ x^{2} + 2\ x - 1 =0 \implies x = \frac{- 1 \pm \sqrt{3}}{2}\ (2)$

Kind regards

$\chi$ $\sigma$

The second equation should be:

\(\displaystyle 2x^2+2x+1=0\implies x=\frac{-1\pm i}{2}\)
 
  • #4
Alexstrasuz said:
I have trouble solving this equation
|1/2x+1|=|x|

My answers are x=2 and x=-2/3

Yes, your answers are correct.
Other posts were solving...
|1/2/x+1|=|x|
 
  • #5
RLBrown said:
Yes, your answers are correct.
Other posts were solving...
|1/2/x+1|=|x|

Just to be clear, I was solving:

\(\displaystyle \left|\frac{1}{2x}+1\right|=|x|\)

More often than not, when someone uses 1/2x, they mean 1/(2x) as opposed to (1/2)x.

This is why is is better to use bracketing symbols (or even better, use $\LaTeX$) to remove doubt. :D
 

FAQ: What are the solutions to this absolute value equation?

What is an absolute value equation?

An absolute value equation is an equation that contains the absolute value of a variable. The absolute value of a number is its distance from zero on a number line. So, an absolute value equation is an equation that includes an expression within absolute value bars.

How do you solve an absolute value equation algebraically?

To solve an absolute value equation algebraically, you need to isolate the absolute value expression on one side of the equation. Then, you need to create two separate equations, one with the positive value of the expression and one with the negative value. Solve both equations to find the two possible solutions.

Can an absolute value equation have more than two solutions?

Yes, an absolute value equation can have more than two solutions. This is because the absolute value of a number can be the same for multiple values, such as |-5| = |5| = 5. So, an equation with absolute value can have as many solutions as there are values that make the absolute value expression equal to the given value.

What is the difference between an absolute value equation and an absolute value inequality?

An absolute value equation is an equation, while an absolute value inequality is an inequality. The main difference is that an equation has an equals sign, while an inequality has a greater than or less than sign. Also, an absolute value equation will have a specific solution, while an absolute value inequality will have a range of possible solutions.

Why are absolute value equations important in real-world applications?

Absolute value equations are important in real-world applications because they are used to solve many real-life problems. For example, they can be used to find the distance between two points on a map or the amount of money needed to reach a certain goal. They are also used in physics, engineering, and other fields to model and solve various problems.

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