How to identify transcendental numbers?

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Given the relationship:

$$\pi = \left(\frac{15ab^2c^3}{2d^4}\right)^{\frac{1}{5}}$$

where a, b and c are non-zero positive constants, can it be assumed at least one of a, b or c must be a transcendental number, since $\pi$ is a transcendental number?

After re-arranging we get:

$$\frac{15}{2} = \frac{d^4\pi^5}{ab^2c^3} .$$

Now the expression on the right must be a rational number. Can I assume one (or 3?) of the constants is/are a transcendental number that somehow cancels out $\pi$ being a transcendental number, to produce a rational result?

Can we deduce anything else about the constants? Must at least one be an irrational number? Is it possible to determine which of the constants are transcendental numbers?

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At least one must be transcendental because the products, quotients, and roots of algebraic numbers are also algebraic. Hence if $a,b,c,d$ all satisfied some respective integer polynomials then so would your expression.

But one is all that can be guarunteed. For example, take $a=\frac{2}{15}\pi ^5$ and $b=c=d=1$ as an example where only one variable is transcendental (or irrational for that matter).