How to calculate LCM for rational equations ?

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In summary, to calculate an LCM for a rational function, first factor all denominator polynomials completely. Then, make a list containing one copy of each factor, all multiplied together. The power of each factor in the list should be the highest power that factor is raised to in any denominator. Finally, the list of factors and powers generated is the LCM. It is not necessary to write out powers as products when factoring completely.
  • #1
kupid
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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.

View attachment 6872

4x = 2.2.x , x2 = x.x , 2x2 =2.x.x

So LCM = 2.2.x.x = 4x2

I still don't understand this clearly ...
 

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  • #2
Hey kupid,

Let's run through the steps.

kupid said:
To calculate an LCM for a rational function, follow these steps:
1. Factor all denominator polynomials completely.

$4x=2^2\cdot x,\quad x^2,\quad 2x^2 = 2\cdot x^2$

kupid said:
2. Make a list that contains one copy of each factor, all multiplied together.

$2\cdot x$

kupid said:
3. The power of each factor in that list should be the highest power that factor is
raised to in any denominator.

$2^2\cdot x^2$

kupid said:
4. The list of factors and powers you generated is the LCM.

$LCM=2^2\cdot x^2 = 4x^2$
 
  • #3
Is there any mistake in the above post , because i am a bit confused .

To calculate an LCM
for a rational function, follow these steps:
1. Factor all denominator polynomials completely.
4x = 2.2.x = 22.x , x2 = x.x , 2x2 =2.x.x
2. Make a list that contains one copy of each factor from the "pairs of factors ", all multiplied together.

2.x

3. The power of each factor in that list should be the highest power that factor is
raised to in any denominator.

22.x2

4. The list of factors and powers you generated is the LCM

LCM = 22.x2 = 4x2
 
  • #4
kupid said:
Is there any mistake in the above post , because i am a bit confused .

No mistake. That's fine. (Nod)

It's just that when we factor completely, there's little point in writing out a power as a product.
We can keep it as a power.
So instead of writing $7x^8=7\cdot x\cdot x\cdot x\cdot x\cdot x\cdot x\cdot x\cdot x$, we can just leave it as $7x^8$.
 
  • #5
OK , Thanks a lot .
 

FAQ: How to calculate LCM for rational equations ?

What is the definition of LCM?

The LCM (Least Common Multiple) is the smallest positive integer that is divisible by two or more numbers without leaving a remainder.

How do you find the LCM for rational equations?

To find the LCM for rational equations, you must first find the LCM for the denominators of the fractions. Then, multiply the fractions by the LCM of their denominators to get equivalent fractions with a common denominator. Finally, add or subtract the numerators as usual.

Can the LCM of rational equations be simplified?

Yes, the LCM of rational equations can be simplified if the resulting fraction can be reduced. However, it is important to simplify the equation only after finding the LCM, not before.

Are there any shortcuts for calculating LCM for rational equations?

Yes, there are a few shortcuts that can make it easier to calculate the LCM for rational equations. One method is to use prime factorization to find the LCM, another is to use the division method, and a third is to use a calculator.

Why is it important to find the LCM for rational equations?

Finding the LCM for rational equations is important because it helps in solving complex equations, simplifying fractions, and finding equivalent fractions. It is also a necessary step in many algebraic operations, such as adding, subtracting, and comparing fractions.

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