Prove that $a, b, c, a+b, a+c, b+c, a+b+c$ can all be the same colour.
136826
Coloring the integers with red, blue, and green
153670
Prove that if $a \mid b$ and $b \mid c$, then $a \mid c$.
104124
Prove or disprove: $A-(B-C) = (A-B)-C$
151038
How to prove (A v B), (A → C), (B → D) therefore (C v D)
12954
Prove if $ac>bc$ and $c>0$, then $a>b$
102133
Prove: $\gcd(a,b) = \gcd(a, b + at)$.
63535
Prove that if $A – C = B – C$ and $A\cap C = B\cap C$ then $A = B$
156468
Solutions to $a+b+c=12$, $a, b, c \in \mathbb{N}_0$
111003
Prove that if $A\triangle B = C\triangle B$, then $A = C$
37744
Prove that given $a,b,c > 0$, it is possible to construct a triangle with sides of length $a,b,c$ if and only if $pa^2+qb^2 > pqc^2$
115719
Find the possible values of |A + B + C |
76049
Prove that if $a|b$ and $a|c$ then $a|(sb+tc)$ for all $s, t \in \mathbb{Z}$
101803
A\(B∩C) = (A\B) ∪ (A\C) how to prove?
142993
Proof of A ⊆ C and B ⊆ C ⇔ A ∪ B ⊆ C
77859
Prove or find a counter example to the claim that for all sets A,B,C if A ∩ B = B ∩ C = A ∩ C = Ø then A∩B∩C ≠ Ø
2289
Prove that if $\gcd( a, b ) = 1$ then $\gcd( ac, b ) = \gcd( c, b ) $
55441
Check: For the integers $a,b,c$ show that $\gcd(a,bc)=\gcd(a,\gcd(a,b)\cdot c)$