The trinomial expression is .

The trinomial compare to general trinomial expression: , So a = 2, b = 9, c = 18.

To find two numbers with a sum of 9 and a product of .

This trinomial list of the factors of 36, and look for the pair of factors is a sum of 9.

Factors of 36	Sum of factor
\ 4, 9 \ 2, 18 \ 3, 12 \	\ 5 \ 16   \ 9 \

The correct factors are 3 and 12.

To factor trinomials of the form , find two integers, m and n, with a sum equal to b and a product equal to c.

Then write  .

Group terms with common factors.

Combine like terms using distributive property: ac  bc = (a b)c.

Check:

To check the solution by multiply the two factors.

    (Using FOIL method)

Product of two different sings is negative.

Combine like terms using distributive property: ac + bc = (a + b)c.

The solution is "true".

The solution is .