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 30: 10, 3 (or) 3, 10 (or) 6, 5 (or) 5, 6 (or) 15, 2 (or) 2, 15.

The correct factors are 6, 5 and 30, So m = 6, n = 5.

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 5 from each side)

Solve for second factor .

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

                   (Add 6 to each side)

The roots are  5, and 6.