Prove that if $A=BQ$ then $A=B$
158845
Given $A$ and $B$ positive-definite matrices and $Q$ unitary matrix, prove that if $A = BQ$, then $A=B$.
29935
If $a, b, c, d>0$ and $abcd=1$ prove that an inequality holds true
21726
Show that if $(b,c)=1$, then $(a,bc)=(a,b)(a,c)$.
71012
If $a, b$ are positive integers such that $a|b^2, b^2|a^3,....$ then $a=b$.
34768
Proving $(p \oplus q) \oplus r=p \oplus (q \oplus r)$
151852
How to prove $A \subset B \iff A \cup B = B$
26766
Proving : $A \cap (B-C) = (A \cap B) - (A \cap C)$
56399
Proof for $A \cup B = B$ if and only if $A \subset B$
34693
Prove $E^{\mathbb Q}[Y]=E^{\mathbb P}[XY]$ if $E^{\mathbb P}[X]=\mathbb P(X>0)=1$ and $ \mathbb Q(A)=E^{\mathbb Q}[X1_A] $
6096
If $A+B=AB$ then $AB=BA$
62474
If $AB=I_n$ and $BA=I_m$ then $n=m$.
11168
Proof of divisibility: if $a|b$ and $a|(b+c)$ then $a|c$
13415
How to show if $A \subseteq B$, then $A \cap B = A$?
13012
Why can a = b imply 2 = 1?
123555
Proving that if $ab=e$ then $ba=e$
20878
If $(a,b)=1$ then prove $(a+b, ab)=1$.
74222
If $a+b=1$ then $a^{4b^2}+b^{4a^2}\leq1$