Invertible matrices modulo $29$.
55719
Order of general- and special linear groups over finite fields.
1425
The Chinese Remainder Theorem for Rings.
96326
Number of $q$-th residues modulo $n$
65432
Prove that every elementary matrix is invertible, and the inverse is again an elementary matrix.
27865
What is the number of invertible $n\times n$ matrices in $\operatorname{GL}_n(F)$?
154581
Ring of matrices isomorphic to $O := \left\{a+b\frac{1+\sqrt{D}}{2}: a, b \in \mathbb{Z} \right\}$
127127
Prove condition number of a invertible matrix is atleast one
113169
Number of $\pm 1$ matrices whose determinant is negative or zero
8557
Invertible Matrices are dense
52040
"Inverse" of an $n\times k$ matrix.
74341
Proving an invertible matrix which is its own inverse has determinant $1$ or $-1$
148946
If $\mathbf{A}$ is a $2\times 2$ matrix that satisfies $\mathbf{A}^2 - 4\mathbf{A} - 7\mathbf{I} = \mathbf{0}$, then $\mathbf{A}$ is invertible
141909
Prove ${2}^{n}\cdot(2m+1)-1 $ is invertible
35801
Traceless matrices and commutators
39969
Algorithms for computing multiplicative order modulo $n$
74460
Matrices A+B=AB implies A commutes with B
139162
Complex number isomorphic to certain $2\times 2$ matrices?