Groups and FieldsMediumA Gallery of Groups ShareA Gallery of Groups · Medium problemHow many of the 54=6255^4=62554=625 matrices (abcd)\begin{pmatrix}a&b\\c&d\end{pmatrix}(acbd) with entries a,b,c,d∈Z5a,b,c,d\in\mathbb Z_5a,b,c,d∈Z5 belong to GL(2,Z5)GL(2,\mathbb Z_5)GL(2,Z5) (that is, have ad−bc≢0(mod5)ad-bc\not\equiv0\pmod5ad−bc≡0(mod5))?Check Show answer Walk through it step by step Practice more like this Review this concept