This document discusses complex formulas in Microsoft Excel, including: 1. Complex formulas contain more than one mathematical operation, as opposed to simple formulas which only contain one operation. The order of operations must be followed when writing complex formulas. 2. The order of operations in Excel is: parentheses, exponents, multiplication/division (from left to right), and addition/subtraction (from left to right). 3. Formulas can contain absolute, relative, or mixed references. Absolute references keep the row and column constant when copied, relative references change the row and column, and mixed references are a combination.