\"\"

\

Original function is \"\"

\

Replace x = 3 in original function.

\

\"\"

\

\"\"    (Evaluate powers: \"\")

\

\"\"          (Add: \"\")

\

\"\"               (Subtract: \"\")                                    \"\"

\

Replace x = 1 in original function.

\

\"\"

\

(Evaluate powers:\"\")

\

\"\"

\

\"\"              (Product of two same signs is positive)

\

\"\"                          (Add: \"\")               \"\"

\

\"\" and \"\".