(a+b)(c-d)

To simplify the expression (a+b)(c-d), you will need to distribute the terms within the parentheses.

Step 1: Distribute a to both c and -d: (a+b)(c-d) = ac - ad

Step 2: Distribute b to both c and -d: (a+b)(c-d) = ac - ad + bc - bd

So, the simplified form of (a+b)(c-d) is ac - ad + bc - bd.