\"\"

\

Let \"\" and \"\" are two solutions of the quadratic equation, then the quadratic equation can be written as

\

\"\".\"\"

\

The solutions of the quadratic equation are \"\"and \"\".

\

The quadratic equation is \"\".

\

Apply foil method : \"\".

\

\"\"

\

Apply formula : \"\".

\

\"\"

\

\"\".\"\"

\

The quadratic equation is \"\".