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A number $x$ is equal to $7\cdot24\cdot48$. What is the smallest positive integer $y$ such that the product $xy$ is a perfect cube?

User Kywillis
by
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2 Answers

5 votes

Answer: 588

Explanation:

User Vladimir Sizikov
by
3.2k points
5 votes

Take the prime factorization of
x.


x = 7*24*48 = 7*(2^3*3)*(3*2^4) = 2^7*3^2*7

If
xy is a perfect cube, then the smallest
y that makes this happen is
y=2^2*3*7^2 = \boxed{588}. We "complete" the cube by introducing just enough factors to get each prime power to be a multiple of 3.

User Manku
by
3.3k points