pt. 1. Numbers and equations. What algebra is
Equations and their solutions
Numerical solution of equations
pt. 2. The formulaic approach to equations. Combinatoric solutions I: quadratic equations
Combinatoric solutions II: cubic equations
pt. 3. Resolvents. From combinatorics to resolvents
The search for resolvents
pt. 4. Abstract algebra. Existence and constructibility of roots
The breakthrough: Galois Theory
Modern Algebra / Roger Cooke.