Proving $\mid \parallel x \parallel - \parallel y \parallel \mid$ $\leqq$ $\parallel x-y \parallel$?
3820
Prove that $||x|-|y||\le |x-y|$
76347
Shorter proof for some equvalences
83407
How to show that that $q \mid p-1$?
85713
Showing Parallelism is an equivalence relation in $\Bbb R ^2$
119118
Prove $n\mid \phi(2^n-1)$
116215
Prove that $P(A \cap B\mid C)=P(A \mid (B \cap C))P(B\mid C)$
151038
How to prove (A v B), (A → C), (B → D) therefore (C v D)
152311
Proving expression$\geq 2$, where variables are $x,y,z$
77164
If $a \mid m$ and $(a + 1) \mid m$, prove $a(a + 1) | m$.
127293
Prove that $(a-b) \mid (a^n-b^n)$
138894
Prove that if $3\mid(a^2+b^2)$,then $3\mid a$ and $ 3\mid b$
2455
Prove that $\left(\sum^n_{k=1}x_k\right)\left(\sum^n_{k=1}y_k\right)\geq n^2$
46286
Prove if $a\mid b$ and $b\mid a$, then $|a|=|b|$ , $a, b$ are integers.
135779
Prove the following: If $a \mid bc$, then $a \mid \gcd(a, b)c$.
67313
Proving $\{(x_1, x_2) \in \mathbb{R}^2_{+} \mid x_1 x_2 \geq 1\}$ is convex
145447
bilinear form - proof
114867
Prove $\forall n\geq 2,n\in\mathbb{Z}$, $(n+1)\mid(n^3+1)$