Algebra

Simultaneous
equations
These lessons explain what simultaneous equations are,
methods for solving them, and the reasons why the methods work as they do.
Part 1Part 1 shows what simultaneous equations are and how to solve them graphically
Part 2Part 2 shows how to solve them by equating and by substitution.
Part 3Part 3 shows how to solve them by adding equations.
Part 4Part 4 works through two examples.
Quadratic equationsLessons that deal with solving quadratic equations.
Part 1Part 1 shows the simplest form of quadratic equations and demonstrates its wide range of usefulness despite its simplicity. 
Part 2Part 2 introduces factorising and shows how to solve quadratic equations in which the coefficient of the squared term is equal to 1.
Part 3Part 3 shows how to solve more difficult quadratic equations in which the coefficient of the squared term is greater than 1.
Part 4Part 4 introduces a compact way of factorising quadratic expressions that is more efficient than the conventional method.
Part 5Part 5 shows how to solve quadratic equations by completing the square.
Part 6Part 6 shows how to solve quadratic equations directly by using the quadratic formula.
Part 7Part 7 shows how to determine the nature of the roots of quadratic equations.