## Compute the number of invertible 2×2 matrices over Z/(2)

Solution to Abstract Algebra by Dummit & Foote 3rd edition Chapter 1.4 Exercise 1.4.1 Prove that $|GL_2(\mathbb{F}_2)| = 6$. Solution: $GL_2(\mathbb{F}_2$ consists of precisely those $2 \times 2$ matrices over…