Euclidean Algorithm/Examples/132 and 473

Examples of Use of Euclidean Algorithm

The GCD of $132$ and $473$ is:

$\gcd \set {132, 473} = 11$


Proof

\(\text {(1)}: \quad\) \(\ds 473\) \(=\) \(\ds 3 \times 132 + 77\)
\(\text {(2)}: \quad\) \(\ds 132\) \(=\) \(\ds 1 \times 77 + 55\)
\(\text {(3)}: \quad\) \(\ds 77\) \(=\) \(\ds 1 \times 55 + 22\)
\(\text {(4)}: \quad\) \(\ds 55\) \(=\) \(\ds 2 \times 22 + 11\)
\(\text {(5)}: \quad\) \(\ds 22\) \(=\) \(\ds 2 \times 11\)

Thus:

$\gcd \set {132, 473} = 11$

$\blacksquare$


Sources

  • 1971: George E. Andrews: Number Theory ... (previous) ... (next): $\text {2-2}$ Divisibility: Exercise $1 \ \text{(e)}$