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College+ · Number Theory

Diophantine equations

36 problems in this skill, each with a solver-verified answer key. Answers are checked the moment you submit — with a hint if you want one and a worked solution afterwards.

What the problems look like

A few statements from this skill. Answers, hints and worked solutions live in the practice session.

  1. Warm-up

    Consider Pell's equation x2−8 y2=1x^{2} - 8\,y^{2} = 1. Its fundamental (smallest non-trivial) solution has y=1y = 1. Find the corresponding positive integer xx.

  2. Warm-up

    Consider Pell's equation x2−35 y2=1x^{2} - 35\,y^{2} = 1. Its fundamental (smallest non-trivial) solution has y=1y = 1. Find the corresponding positive integer xx.

  3. Warm-up

    Consider Pell's equation x2−15 y2=1x^{2} - 15\,y^{2} = 1. Its fundamental (smallest non-trivial) solution has y=1y = 1. Find the corresponding positive integer xx.

Problems shown under their original terms: Generated (template, solver-computed).

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