MHB Find positive integers for both a and b

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The problem involves finding positive integers a and b that satisfy the equation (√[3]{a} + √[3]{b} - 1)² = 49 + 20√[3]{6}. Attempts to expand the left side or rewrite the right side as a square of a sum have not yielded results. A proposed solution involves expressing √(49 + 20√[3]{6}) in the form α + β√[3]{6} + γ√[3]{36}, leading to the identification of values α = -1, β = γ = 2. This results in the integers a = 48 and b = 288, or vice versa. The discussion highlights the challenge of the problem, which is sourced from the British Math Olympiad.
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I have a question relating to solving for both a and b in the following question:

Find positive integers a and b such that:

$\displaystyle \left(\sqrt[3]{a}+\sqrt[3]{b}-1 \right)^2=49+20\sqrt[3]{6}$

This one appears to be tough because it doesn't seem right to expand the left hand side and I have tried that but it lead me to nowhere closer to finding both integers values for a and b.

Also, I've tried to work on the right hand side as my effort revolved around rewriting it as the square of sum of two terms but this has not been a fruitful approach as well.

Do you guys have any idea on how I can solve this one, please?

Thanks in advance.
 
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anemone said:
Find positive integers a and b such that:

$\displaystyle \left(\sqrt[3]{a}+\sqrt[3]{b}-1 \right)^2=49+20\sqrt[3]{6}$

One way: expressing $\sqrt{49+20\sqrt[3]{6}}=\alpha +\beta \sqrt[3]{6}+\gamma \sqrt[3]{36}$ with $\alpha,\beta,\gamma\in\mathbb{Q}$ we get $\alpha=-1,\beta=\gamma=2$. Now, identifyng, we obtain $a=48,b=288$ (0r reciprocally).

P.S. For the first step, we have used that a basis of $\mathbb{Q}(\sqrt[3]{6})$ over $\mathbb{Q}$ is $B=\{1,\sqrt[3]{6},\sqrt[3]{36}\}$. I ignore if at Olympiad level the students cover some similar property (of course without using the theory of extension fields).
 
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