Practice problems of Rational Equations ?

In summary, to calculate the LCM of rational equations, you need to factor all denominator polynomials and then make a list of all the factors with the highest power for each factor. This list will be the LCM.
  • #1
kupid
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Does anyone know where i can find some practice problems of Rational Equations ?
 
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  • #3
I don't know how to take the LCM of the denominators when the denominators are algebraic terms .

For example ,

View attachment 6704

How do i take the LCM there ? Do we simply multiply the terms in the denominator ?
 

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  • #4
kupid said:
I don't know how to take the LCM of the denominators when the denominators are algebraic terms .

For example ,
How do i take the LCM there ? Do we simply multiply the terms in the denominator ?

Hi kupid,

The least common denominator (LCD) of a set of fractions is the least number that is a multiple of all the denominators.
In this case that means indeed that we simply multiply the denominators.
That only changes if the denominators have a factor in common.
 
  • #5
Thanks

But i don't know how to check for common factors when the denominators are algebraic terms .

How do we check for common factors when the denominators are algebraic terms ?
 
  • #6
kupid said:
Thanks

But i don't know how to check for common factors when the denominators are algebraic terms .

How do we check for common factors when the denominators are algebraic terms ?

By factoring denominators to the form (x-a)(x-b)(x-c).
If both denominators contain (x-a), then the LCD has (x-a) only once.
 
  • #7
Oh , That is how you find the LCM in such cases ? Thanks a lot :-)
 
  • #8
using the example you posted earlier ...

$\dfrac{4}{x+2} + 3 = \dfrac{3x}{x-3}$

$\dfrac{4\color{red}{(x-3)}}{(x+2)\color{red}{(x-3)}} + \dfrac{3\color{red}{(x+2)(x-3)}}{\color{red}{(x+2)(x-3)}}= \dfrac{3x\color{red}{(x+2)}}{(x-3)\color{red}{(x+2)}}$

$4(x-3) + 3(x+2)(x-3) = 3x(x+2)$ ; $x \ne \{-2,3\}$
 
  • #9
  • #10
bottom line (no pun intended) ... just make all the denominators the same using the least number of common factors possible
 
  • #11
Thanks ,To calculate an LCM for a rational function, follow these steps:
1. Factor all denominator polynomials completely.
2. Make a list that contains one copy of each factor, all multiplied together.
3. The power of each factor in that list should be the highest power that factor is
raised to in any denominator.
4. The list of factors and powers you generated is the LCM.
 

FAQ: Practice problems of Rational Equations ?

What are rational equations?

Rational equations are equations that involve fractions with variables in the numerator and/or denominator. They can be solved using algebraic methods, such as cross-multiplication, or by finding a common denominator.

How do I know if a rational equation has extraneous solutions?

Extraneous solutions are solutions that do not satisfy the original equation. To determine if a rational equation has extraneous solutions, you should check your solutions by plugging them back into the original equation. If they do not make the equation true, then they are extraneous solutions.

Can rational equations have more than one solution?

Yes, rational equations can have more than one solution. In fact, most rational equations will have multiple solutions. It is important to check your solutions to ensure that they are all valid.

What are the steps to solving a rational equation?

The steps to solving a rational equation are:

  1. Identify any restrictions on the variable (values that would make the equation undefined)
  2. Cross-multiply or find a common denominator to eliminate fractions
  3. Solve the resulting equation
  4. Check your solutions for validity

How can rational equations be applied in real life?

Rational equations have many real-life applications, such as calculating rates, proportions, and unit conversions. They can also be used in finance to calculate interest rates or in science to model relationships between variables. Understanding how to solve rational equations can help in making informed decisions and solving problems in various fields.

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