When subtracting trinomials, first distribute the negative sign to the expression being subtracted, and then remove the parentheses:

Next, identify and group the like terms in order to combine them: .

Find the difference:

Distribute the negative to the second trinomial:

Combine like terms:

To subtract these two trinomials, you first need to flip the sign on every term in the second trinomial, since it is being subtrated:

Next you can combine like terms. You have two terms with , two terms with , and two terms with no variable: