Intuitive proof for $(a, b) = (a', b')$.
25825
Proof that $\gcd(ax+by,cx+dy)=\gcd(x,y)$ if $ad-bc= \pm 1$
95935
Prove A = $(A \cap B) \cup (A \cap B^c)$ using the distributive and associative law.
13136
Element chasing proof that $(A\setminus C)\setminus(B\setminus C) = (A\setminus B)\setminus C$
53660
Show that $ a，b，c, \sqrt{a}+ \sqrt{b}+\sqrt{c} \in\mathbb Q  \implies  \sqrt{a},\sqrt{b},\sqrt{c} \in\mathbb Q $
104124
Prove or disprove: $A-(B-C) = (A-B)-C$
63535
Prove that if $A – C = B – C$ and $A\cap C = B\cap C$ then $A = B$
102133
Prove: $\gcd(a,b) = \gcd(a, b + at)$.
51538
Intuition for $\,c\mid a,b \iff c\mid \gcd(a,b)$
46286
Prove if $a\mid b$ and $b\mid a$, then $|a|=|b|$ , $a, b$ are integers.
49578
Proving $a\mathbb{Z}\cap b\mathbb{Z}=[a,b]\mathbb{Z}$
139841
Proving $A\setminus(B\setminus C)$ is not equal to $(A\setminus B)\setminus C$
115460
Proving $a\mid b^2,\,b^2\mid a^3,\,a^3\mid b^4,\ldots\implies a=b$ - why is my approach incorrect
76347
Shorter proof for some equvalences
93557
Intuitively, why does (B → S) ≡ (¬B ∨ S)?
13167
Prove $A = (A \setminus B) \cup (A \cap B)$
143130
Proving that the supremum of $(a,b)$ is $b$.
116215
Prove that $P(A \cap B\mid C)=P(A \mid (B \cap C))P(B\mid C)$