Which Method is Correct for Solving Rational Equations?

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In summary, the conversation discusses solving a rational equation using two different methods and determining the correct answer. The first method results in x=1 while the second method results in x=4/3. It is concluded that the second method is correct and the first method is incorrect due to a mistake in multiplying both sides of the equation. The correct answer is x=4/3.
  • #1
anonymous12
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Homework Statement




photo.jpg


In the picture above, I solved the rational equation using two different methods. In the first method I got x = 1 and in the second method I got x = 4/3. Which answer is correct or are both of them incorrect? Thanks.
 
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  • #2
If you're going to do your work on paper, and then take a picture of it and upload it, at least do us the courtesy of
1) providing a reasonably decent picture
2) providing a picture that is oriented the right way
 
  • #3
The rational equation is:
[itex]\displaystyle \frac{3}{x+2}-\frac{1}{x}=\frac{1}{5x}\,.[/itex]​

It's easy to check by plugging in the answers.

[STRIKE]Explain in more detail how you arrived at those answers so we can help you.[/STRIKE]

Added in edit:

Never mind. You do show your work in a hard to read sideways image.

The first method is wrong because you failed to multiply the right side by x(x+2). You must multiply BOTH SIDES of the equation by the same thing.

The second method was OK. You multiplied both sides by an extra x, which gave you an extraneous solution. x=4/3 is correct.
 
Last edited:
  • #4
EDIT: Yup, 4/3 is the correct answer. Thanks for the help.
 

FAQ: Which Method is Correct for Solving Rational Equations?

1. What is a rational equation?

A rational equation is an equation that contains one or more rational expressions. A rational expression is a fraction with polynomials in the numerator and denominator.

2. How do you solve a rational equation?

To solve a rational equation, you need to cross-multiply and combine like terms to eliminate any fractions. Then, solve the resulting equation for the variable.

3. Can you provide an example of solving a rational equation?

For example, let's solve the equation 2/(x+1) = 3/4. Cross-multiplying, we get 8 = 3(x+1). Expanding the parentheses, we get 8 = 3x + 3. Subtracting 3 from both sides, we get 5 = 3x. Dividing both sides by 3, we get x = 5/3.

4. What are extraneous solutions in rational equations?

Extraneous solutions are solutions that satisfy the resulting equation but do not satisfy the original equation. These can occur when we multiply both sides of the equation by a variable that could potentially be zero.

5. Are there any special cases when solving rational equations?

Yes, there are a few special cases when solving rational equations. One is when the rational expressions have the same denominator, in which case you can simply equate the numerators and solve for the variable. Another is when the rational expression is equal to zero, in which case you can solve for the variable by setting the numerator equal to zero.

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