proof that if a|b and b|c then a|c
56878
Proof that $a\mid b \land b\mid c \Rightarrow a\mid c $
140167
Proving $A+A'B=A+B$ without truth tables
20878
If $(a,b)=1$ then prove $(a+b, ab)=1$.
75199
$a \equiv b \pmod n$ and $c\equiv d \pmod n$ implies $ac \equiv bd \pmod n$
13074
Prove Logical Equivalence
155545
Showing that $a \mid b$ and $b \mid a$ if and only if $a= \pm b$.
80009
Prove that $| |a|-|b| | \le |a-b|$
41099
If $A \subseteq C$ and $B \subseteq D$ then $A \times B \subseteq C \times D$
143130
Proving that the supremum of $(a,b)$ is $b$.
80759
Proving $A\times (B\cap C)=(A \times B)\cap (A\times C)$.
21726
Show that if $(b,c)=1$, then $(a,bc)=(a,b)(a,c)$.
80255
How to prove that $|a-b|<\epsilon$ implies $|b|-\epsilon<|a|<|b|+\epsilon$?
111003
Prove that if $A\triangle B = C\triangle B$, then $A = C$
111800
If $a|c$ and $b|d$, is it true that $ab|cd$?
29935
If $a, b, c, d>0$ and $abcd=1$ prove that an inequality holds true
137626
If $a,b,c$ are positive integers,and $\cfrac{a}{b}+\cfrac{b}{c}+\cfrac{c}{a}$ and $\cfrac{b}{a}+\cfrac{c}{b}+\cfrac{a}{c}$ are integers then $a=b=c$
67483
Show that $|a-b|<\epsilon \Rightarrow |a|<|b|+\epsilon$