The given function is .

                         (Substitute f(x) = 0)

Apply multiplication property of addition: If a = b then .

And multiply each side by .

Apply zero product property: .

The factors of 4: 2, 2 (or) 4, 1 (or) 1, 4.

The correct factors are 4,1 and 4, So m = 4, n = 1.

Then write the factors form .

             (Group terms with common factors)

                (Factors the grouping terms)

                        (Take out common term )

Apply zero product property: If then a = 0 (or) b = 0.

Solve for first factor .

Apply subtraction property of equality: If a = b then .

                            (Subtract 4 from each side)

Solve for second factor .

Apply subtraction property of equality: If a = b then .

                           (Add 1 to each side)

The roots are 4, and 1.