Finding all elements in $x\in U_{143}$ such that $x^2=1 \pmod{143}$
42032
Find all solutions to $x^2\equiv 1\pmod {91},\ 91 = 7\cdot 13$
104176
$15x\equiv 20 \pmod{88}$ Euclid's algorithm
145617
Is there any simple trick to solve the congruence $a^{24}\equiv6a+2\pmod{13}$?
125330
How to find element g order q, given 2 large primes p and q where q|p-1
63194
Find all integer solutions to $x^2-2y^2=1$
4967
Fractions with large elements
135465
Group theory proof of existence of a solution to $x^2\equiv -1\pmod p$ iff $p\equiv 1 \pmod 4$
127945
Number of solutions to the congruence $x^q \equiv 1 \mod p$.
109490
Modular arithmetic problem (mod $13$)
30045
Solving linear congruences by hand: modular fractions and inverses
119052
Finding invertible elements in $\mathbb{Z}/m\mathbb{Z}$
22962
How to show $\binom{2p}{p} \equiv 2\pmod p$?
73743
Number of elements in the quotient ring $\mathbb{Z}[X]/(X^2-3, 2X+4)$
89989
A set of integers whose elements all divide $2015^{200}$ but do not divide each other
44033
Number theory lemma - $x^2 \equiv 1 \pmod p$ implies $x\equiv\pm 1\pmod p$
17609
Finding the remainder of $11^{2013}$ divided by $61$
68960
How to solve $ 13x \equiv 1 ~ (\text{mod} ~ 17) $?