Using prime factorization to solve it, but am still stuck?

2020-08-09 10:21 pm

回答 (3)

2020-08-09 11:06 pm
✔ 最佳答案
1500k = 2² × 3 × 5³ × k

If 1500k is both a perfect square and a perfect cube,
the smallest value of 1500k = 2⁶ × 3⁶ × 5⁶

Hence, 2² × 3 × 5³ × (Smallest k) = 2⁶ × 3⁶ × 5⁶
Smallest k = 2⁴ × 3⁵ × 5³ = 486000
2020-08-09 10:54 pm
For a prime number to have a perfect square and perfect cube
the perfect number must be n⁶ 
n⁶ = (n²)³ 
n⁶ = (n³)² 
-----------------------

Prime factors of 1500
5³ * 2²  * 3
-----------------------

5⁶ = 5³ * 5³ 
2⁶ = 2² * 2⁴ 
3⁶ = 3 * 3⁵ 

Therefor 
k = 5³ * 2⁴ * 3⁵ 
k = 486,000 <–––––––
2020-08-09 10:49 pm
Given that 1500k is both a perfect square and a perfect cube, 
write down the smallest possible value of k.


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