I can tell you a shortcut:

There are two products.

One is (1) and the other is (2) .

The coefficient of in the combined product will be obtained by adding the following coefficients:

1. The coefficient of in (1) multiplied by the coefficient of in (2).

2. The coefficient of in (1) multiplied by the coefficient of in (2).

3. The coefficient of in (1) multiplied by the coefficient of in (2).

4. The constant term of (1) multiplied by the coefficient of in (2).