SOLUTION: If the product 19845k is a perfect cube, what is the smallest possible value of k if k is a positive integer?

Algebra ->  Finance -> SOLUTION: If the product 19845k is a perfect cube, what is the smallest possible value of k if k is a positive integer?      Log On


   



Question 814037: If the product 19845k is a perfect cube, what is the smallest possible value of k if k is a positive integer?
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
19845k = 3*3*3*3*5*7*7k = 34*51*72k

by a value that will make it
a perfect cube, we much choose a value that will cause
every factor to have an exponent which is a multiple of 3.

The 34 must be multiplied by 32 so it
will become 36 

The 51 must be multiplied by 52 so it
will become 53

The 72 must be multiplied by 71 so it
will become 73


So we must multiply 34*51*72 by
32*52*71

So k = 32*52*71 = 9*25*7 = 1575

So the smallest possible positive integer value of k is 1575

Checking:

19845*1575 = 31255875 = 315³ 

Edwin