The title of this post is probably a bit confusing specially the quadratic form part of it.

What exactly is an equation of quadratic form anyways? First you need to have a polynomial and your polynomial needs a degree to be >= 2.

For example:

Now how can we solve this equation? We have to use U substitution to get the equation in a form that we can factor.

• Find the U in the equation and define it
• Replace x values in the equation with the u
• Factor the equation
• Solve for U
• Replace U back into the equation
• Solve for X
• Check with the original equation

Example: