Prove $[a,b] \sim (c,d]$
31244
Is this a correct bijection between $(0,1]$ and $[0,1]$?
56166
Prove that $\frac{a}{b+2c+3d}+\frac{b}{c+2d+3a}+\frac{c}{d+2a+3b}+\frac{d}{a+2b+3c} \geq \frac{2}{3}.$
29935
If $a, b, c, d>0$ and $abcd=1$ prove that an inequality holds true
49501
Prove that : $(a-b)(a-c)(a-d)(b-c)(b-d)(c-d)$ divisible by $12$
67483
Show that $|a-b|<\epsilon \Rightarrow |a|<|b|+\epsilon$
57096
Show that $\max{\{|a|+|b|,|c|+|d|\}} \leq \max{\{|a|,|c|\}}+\max{\{|b|,|d|\}}.$
33633
Re:$ (a,b,c,d)=(pr+qs, qr-ps,pr-qs,ps+qr) $
1821
Proving $f(C) \setminus f(D) \subseteq f(C \setminus D)$ and disproving equality
62755
The simplest way of proving that $|\mathcal{P}(\mathbb{N})| = |\mathbb{R}| = c$
95852
Prove that $(a+b)(b+c)(c+a) \ge8$
26766
Proving : $A \cap (B-C) = (A \cap B) - (A \cap C)$
87303
Show that $\frac{a}{c} + \frac{b}{d} +\frac{c}{a} + \frac{d}{b}\le-12$
44705
Prove that $\frac{1}{a^3(b+c)}+\frac{1}{b^3(a+c)}+\frac{1}{c^3(a+b)}\ge \frac32$
5369
Proving the inequality $|a-b| \leq |a-c| + |c-b|$ for real $a,b,c$
53660
Show that $ a，b，c, \sqrt{a}+ \sqrt{b}+\sqrt{c} \in\mathbb Q  \implies  \sqrt{a},\sqrt{b},\sqrt{c} \in\mathbb Q $
104124
Prove or disprove: $A-(B-C) = (A-B)-C$
39953
$a\mid b,\ c\mid d\,\Rightarrow\ ac\mid bd $ $\ \, \bf\small [Divisibility\ Product\ Rule]$