Prove if d | a, then d | ca for any integer c. Correction
39953
$a\mid b,\ c\mid d\,\Rightarrow\ ac\mid bd $ $\ \, \bf\small [Divisibility\ Product\ Rule]$
23869
Prove the implication "if $ac>bc$ and $c>0$, then $a>b$" using the contrapositive
45370
Is it true that $|d(x, z) - d(y, z)| \leq d(x, y)$ and how do I prove it?
135779
Prove the following: If $a \mid bc$, then $a \mid \gcd(a, b)c$.
66563
Is $ (A∪B)×(C∩D)=(A∪C)×(B∪D)$ true for all sets A,B,C and D?
75199
$a \equiv b \pmod n$ and $c\equiv d \pmod n$ implies $ac \equiv bd \pmod n$
30136
Proof that a Combination is an integer
13026
Prove that if AB=I_m, then rk(A)=rk(B).
26766
Proving : $A \cap (B-C) = (A \cap B) - (A \cap C)$
1821
Proving $f(C) \setminus f(D) \subseteq f(C \setminus D)$ and disproving equality
111003
Prove that if $A\triangle B = C\triangle B$, then $A = C$
39621
Let a, b, c, d be rational numbers...
51321
Prove that $A = B = C = D$
114667
$d\mid a,b \iff d\mid\gcd(a,b) \ $ [GCD Universal Property]
43310
Proving $A\cap(B-C)$ is equal to $(A\cap B)-(A\cap C)$
102042
If $X_n \stackrel{d}{\to} X$ and $c_n \to c$, then $c_n \cdot X_n \stackrel{d}{\to} c \cdot X$
77547
Find integers $a,b,c,d$ such that