Prove multiplicative inverses in reduced residue system
31917
If $q$ is coprime to $a$ then $a\mid nq-1,\,$ so $q$ is invertible mod $a$
75625
Complete residue system proof
145900
Proof of a double summation reduction identity
134075
Inverse of $A^{-1}+B^{-1}$
130162
A complete residue system from an arithmetic progression
101057
Show that $1^{p-1} + 2^{p-1} +\ldots + (p-1)^{p-1} \equiv -1 \mod p$
105225
Number Theory: Complete set of residues modulo $n$
111505
Proof $\binom{p-1}{k}\equiv (-1)^k \mod{p}$
107397
Algebraic proof for the identity $\sum_{k=0}^m(-1)^{m-k}{{n \choose {k}}}= {{n-1}\choose m}$
99815
Dividing versus multiplying by inverse in modular arithmetic
101313
Minimal polynomial, determinants and invertibility
120627
Reducibility of polynomials modulo p
75141
Quotient-Remainder Theorem Proving
130300
Proof that every quadratic residue has two roots, modulo a prime
122519
Multiplicative Functions
64742
Prove a residue matrix $A$ (with coefficients in $\mathbb Z_n)$ has an inverse if and only if $\gcd(\det A,n) = 1$
121706
Show $\text{det}(A)$ is divisible by $2^{n-1}$