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Find the least common multiple of the expressions:

1. 2m2n; 3mn3; 9n2p  

 

2. 5x3 + 15x2; x2 – 6x + 9; 2x2 – 6x  

 Mar 2, 2015

Best Answer 

 #5
avatar+128474 
+10

For the second one, we have

2. 5x3 + 15x2; x2 – 6x + 9; 2x2 – 6x

Factor each

5x^2(x + 3), (x -3)^2, 2x(x -3)

And the LCM is

10x^2(x + 3)(x -3)^2 =  {you could expand this...if you want}

10x^2 (x ^2 - 9) ( x- 3) =

10x^2 (x^3 - 3x^2 - 9x + 27) =

10x^5 - 30x^4 - 90x^3 + 270x^2

 

 Mar 3, 2015
 #2
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0

Thanks. I guess I did something wrong because I got 18 as my answer, not 54. 

 Mar 3, 2015
 #4
avatar+118609 
+5

Sorry, my first answer was garbage and I have whited it. 

I must have had a brain aneuryism,  or a chronic case of CDD at the very least. 

 

2m2n; 3mn3; 9n2p  

2m2n; 3mn3; 32n2p  

The lowest common multiple for the 2'a is 2

The lowest common multiple for the 3's is 3^2=9.     

the lowest common multple for the m pronumeral is m^2

the lowest common multple for the n pronumeral is n^3

the lowest common multiple for the p pronumeral is p

Put it all together and you get  

 

  $$LCM=18m^2n^3p$$

 Mar 3, 2015
 #5
avatar+128474 
+10
Best Answer

For the second one, we have

2. 5x3 + 15x2; x2 – 6x + 9; 2x2 – 6x

Factor each

5x^2(x + 3), (x -3)^2, 2x(x -3)

And the LCM is

10x^2(x + 3)(x -3)^2 =  {you could expand this...if you want}

10x^2 (x ^2 - 9) ( x- 3) =

10x^2 (x^3 - 3x^2 - 9x + 27) =

10x^5 - 30x^4 - 90x^3 + 270x^2

 

CPhill Mar 3, 2015
 #6
avatar+118609 
0

Thanks Chris :)

 Mar 3, 2015
 #7
avatar
+5

Thanks guys! Both my answers were corrrect! :)

 Mar 3, 2015
 #8
avatar+118609 
0

That is excellent!   

 Mar 3, 2015

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