Quick proof with Euclid's Algorithm
3694
Show $GCD(a_1, a_2, a_3, \ldots , a_n)$ is the least positive integer that can be expressed in the form $a_1x_1+a_2x_2+ \ldots +a_nx_n$
93685
Erdős's proof of Sylvester's theorem
77253
Proof of Lagrange Identity
138178
Proving the number of iterations in the Euclidean algorithm
138851
Euclid's Lemma in a PID: irreducibles are prime: $ \pi\mid ab\Rightarrow \pi\mid a\,$ or $\pi\mid b$
78359
Induction and Recursion Proof using Catalan Numbers
85204
Winding numbers are continuous: The proof was too easy
149993
Use the Euclidean algorithm to prove that gcd(na, nb) = n gcd(a, b).
90904
Combinatorial proof of an identity with squared binomial coefficients
77026
Proof with inequalities
147275
Finding a Eulerian Tour
60596
Euclidean Algorithm for GCD of polynomials
152084
Binomial-Theorem proof
50605
Extended Euclidean algorithm
98722
Understanding Euclid's proof that the number of primes is infinite.
106183
Proof by Induction: Alternating Sum of Fibonacci Numbers
145447
bilinear form - proof