If $19|x^2$ then $19|x$
834
If $p$ is a prime and $p \mid ab$, then $p \mid a$ or $p \mid b$.
121984
Let $f (x)= x^7 -105x + 12$ then which of the following options is correct?
81223
Real Analysis Question: continuity of $f(x) = \sum_{q_n<x} 1/n^2$
15191
If $a^2$ divides $b^2$, then $a$ divides $b$
108429
Show that if $x_n \to x$ then $\sqrt{x_n} \to \sqrt{x}$
127901
If $x^2+y^2 \equiv 0\pmod{p}$, then $p \equiv 1 \pmod{4}$
15821
$\ln(x^2)$ vs $2\ln x$
82630
How is it, that $\sqrt{x^2}$ is not $ x$, but $|x|$?
155136
$x\in \{\{\{x\}\}\}$ or not?
37158
upper limit of $\cos (x^2)-\cos (x+1)^2$ is $2$
82803
Prove that $\lfloor\lfloor x/2 \rfloor / 2 \rfloor = \lfloor x/4 \rfloor$
32742
The limit of $\frac{|A_n|}{n^2}$
155789
Integral values of $x$ for which the expression $x^2+19x+92$ is a perfect square
46400
how do i prove that $17^n-12^n-24^n+19^n \equiv 0 \pmod{35}$
6561
Prove that the expression $5^{2n+1} \cdot 2^{n+2} + 3^{n+2} \cdot 2^{2n+1}$ is divisible by 19.
70164
Proof exercise that the cardinal number of a set in $\mathbb R^2$ is $\frak c$
2554
Show that if $n>2$, then $(n!)^2>n^n$.