Question

$\frac{2abc}{(a+b-c)(b+c-a)(c+a-b)}$ a positive integer

score 286 · Answer 1 · 2016-03-08 18:27:47

286

Views

$\frac{2abc}{(a+b-c)(b+c-a)(c+a-b)}$ a positive integer

Published on 08 Mar 2016 - 18:27

score 629 · Answer 2 · 2026-04-11 21:46:19

629

Views

Is this correct? Prove $5k+3$ is not divisible by $5$ using proof by contradiction

Published on 11 Apr 2026 - 21:46

score 111 · Answer 3 · 2026-04-12 10:42:54

111

Views

Is it possible to know if $X$ is divisible by $Y$ without dividing $X$ by $Y$.

Published on 12 Apr 2026 - 10:42

score 1.1k · Answer 4 · 2026-04-11 12:23:11

1.1k

Views

Palindromes on Keypad and divisibility by $111$

Published on 11 Apr 2026 - 12:23

score 44 · Answer 5 · 2026-04-14 10:37:17

44

Views

Elementary proof: division by integer makes real number smaller.

Published on 14 Apr 2026 - 10:37

score 270 · Answer 6 · 2026-04-14 22:07:42

270

Views

Use the binomial theorem to prove if $m\mid b - a$, then $m \mid b^n - a^n$.

Published on 14 Apr 2026 - 22:07

score 604 · Answer 7 · 2026-04-14 21:48:20

604

Views

Prove that $a^n - b^n$ does not divide $a^n + b^n$

Published on 14 Apr 2026 - 21:48

score 391 · Answer 8 · 2026-03-29 16:00:50

391

Views

How to prove that $a \cdot b$ is not divisible by 5 for $\frac{1}{1} + \frac{1}{2} + ... + \frac{1}{99} + \frac{1}{100} = \frac{a}{b}$?

Published on 29 Mar 2026 - 16:00

score 96 · Answer 9 · 2026-04-14 18:48:39

96

Views

Fibonacci Divisibility Burton's Corollary: $u_m \mid u_n$ if and only if $m \mid n$

Published on 14 Apr 2026 - 18:48

score 161 · Answer 10 · 2016-03-12 22:56:20

161

Views

Prove that $7 | (3^{2n + 1} + 2^{n +2})$

Published on 12 Mar 2016 - 22:56

score 958 · Answer 11 · 2026-03-31 17:49:24

958

Views

Why does dividing a number with $n$ digits by $n$ $9$'s lead to repeated decimals?

Published on 31 Mar 2026 - 17:49

score 120 · Answer 12 · 2026-04-14 21:50:24

120

Views

Prove that for any prime $p$ there exist natural numbers $a,b$ for which $ p$ divides $a^2+b^2+1$

Published on 14 Apr 2026 - 21:50

score 435 · Answer 13 · 2026-04-13 04:13:57

435

Views

Prove that the determinant is a multiple of $17$ without developing it

Published on 13 Apr 2026 - 4:13

score 104 · Answer 14 · 2026-04-13 10:14:17

104

Views

Divisibility problem involving the $2015^{th}$ power

Published on 13 Apr 2026 - 10:14

score 459 · Answer 15 · 2026-04-01 09:55:32

459

Views

If a, b, c are three natural numbers with $\gcd(a,b,c) = 1$ such that $\frac{1}{a}+\frac{1}{b}=\frac{1}{c}$ then show that $a+b$ is a square.

Published on 01 Apr 2026 - 9:55

List Question

$\frac{2abc}{(a+b-c)(b+c-a)(c+a-b)}$ a positive integer

Is this correct? Prove $5k+3$ is not divisible by $5$ using proof by contradiction

Is it possible to know if $X$ is divisible by $Y$ without dividing $X$ by $Y$.

Palindromes on Keypad and divisibility by $111$

Elementary proof: division by integer makes real number smaller.

Use the binomial theorem to prove if $m\mid b - a$, then $m \mid b^n - a^n$.

Prove that $a^n - b^n$ does not divide $a^n + b^n$

How to prove that $a \cdot b$ is not divisible by 5 for $\frac{1}{1} + \frac{1}{2} + ... + \frac{1}{99} + \frac{1}{100} = \frac{a}{b}$?

Fibonacci Divisibility Burton's Corollary: $u_m \mid u_n$ if and only if $m \mid n$

Prove that $7 | (3^{2n + 1} + 2^{n +2})$

Why does dividing a number with $n$ digits by $n$ $9$'s lead to repeated decimals?

Prove that for any prime $p$ there exist natural numbers $a,b$ for which $ p$ divides $a^2+b^2+1$

Prove that the determinant is a multiple of $17$ without developing it

Divisibility problem involving the $2015^{th}$ power

If a, b, c are three natural numbers with $\gcd(a,b,c) = 1$ such that $\frac{1}{a}+\frac{1}{b}=\frac{1}{c}$ then show that $a+b$ is a square.

Trending Questions

Popular # Hahtags

Popular Questions