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MathNet 2015-part-07 — 185 problems (EN–VI) Question 35

Math Olympiad Vault · MathNet 2015-part-07 — 185 problems (EN–VI)

Question 35

Find all ordered 4-tuples of integers $(a, b, c, d)$ (not necessarily distinct) satisfying the following system of equations:

$$
\begin{aligned}
a^{2}-b^{2}-c^{2}-d^{2} & = c-b-2 \\
2 a b & = a-d-32 \\
2 a c & = 28-a-d \\
2 a d & = b+c+31
\end{aligned}
$$