Introduction to solving quadratic equations AND two factoring examples:

This equation is solved by factoring:

Solving a quadratic equation using square roots:

Solving a quadratic equation by completing the square:

This is an introductory level complete-the-square problem (coefficient of x squared is 1, coefficient of x is even):

This is a much more advanced complete-the-square problem:

Solving a quadratic equation using the quadratic formula:

Finding a quadratic equation given the solutions:

The video below shows how to solve an applied problem involving the height of a ball when it tossed upwards from the top of a roof. The solution method is factoring:

Volume application of a quadratic equation:

Right triangle application of a quadratic equation (Pythagorean Theorem):

This is an area problem involving two rectangles. Factoring is used.

This video shows how to solve an applied problem about the area of a parking lot. Don't worry - I didn't draw the cars.

Here's a proof of the quadratic formula (in case you want to know WHY it works).