What Natural Numbers Solve the Equation from POTW #421?

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SUMMARY

The equation presented in POTW #421, $\dfrac{1^4}{x}+\dfrac{2^4}{x+1}+\dfrac{3^4}{x+2}+\cdots+\dfrac{10^4}{x+9}=3025$, requires solving for natural numbers. The correct solutions were provided by forum members castor28 and kaliprasad. Their approaches involved systematic substitution and simplification of the equation to identify valid natural number solutions for x.

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Here is this week's POTW:

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Solve for natural numbers for the identity below:

$\dfrac{1^4}{x}+\dfrac{2^4}{x+1}+\dfrac{3^4}{x+2}+\cdots+\dfrac{10^4}{x+9}=3025$

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Congratulations to the following members for their correct solution! (Cool)

1. castor28
2. kaliprasad

Solution from castor28:
We use the fact that $\displaystyle\sum_{k=1}^n{k^3}=\frac{n^2(n+1)^2}{4}$.

For $x=1$, the LHS becomes:
$$
1^3 + 2^3 + \cdots + 10^3 = \frac{10^2\cdot 11^2}{4}=3025
$$

As this is the required value, $x=1$ is a solution. As the LHS is a decreasing function of $x$, this is the only solution.
 

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