Solutions to $n^2\equiv1 \mod a$
1576
Finding the elements in the group of units of the ring of integers modulo n that are their own inverse.
144802
Prove no solution to $x^2\equiv3\bmod5$
108237
Show $a^p \equiv b^p \mod p^2$
26478
Show that the congruence $x^{p-1} \equiv 1 \pmod {p^2}$ has precisely $p-1$ solutions modulo $p^2$
143754
Finding the solution of the congruence $4x\equiv16\pmod{26}$
41689
Find all solutions: $x^2 + 2y^2 = z^2$
14809
Existence & uniqueness of solutions of linear congruences $\ cx\equiv b\pmod m$
52658
What are the integer solutions to $a^{b^2} = b^a$ with $a, b \ge 2$
59442
Are there $a,b>1$ with $a^4\equiv 1 \pmod{b^2}$ and $b^4\equiv1 \pmod{a^2}$?
108035
solving diophantine equations using congruences
103304
Finding the number of solutions to a diophantine equation
95669
Solutions of $|z| = z^5$ in $\Bbb{C}$?
156468
Solutions to $a+b+c=12$, $a, b, c \in \mathbb{N}_0$
102234
Show $a^p \equiv a \mod 2p$
24837
$x^2+1=0$ uncountable many solutions
83913
Rational solutions of Pell's equation
62161
Solutions of the Pell-type equation $x^2-2y^2=-1$