# How Do You Write An Algebraic Expression?

• The binomial theorem is an identity for all x and y and nonnegative integers n. Each blue ellipse is an expression. Make sure that an expression is what you want. Expressions differ from other related concepts such as equations, formulas, and identities. Each of these is represented by two expressions separated by an equal sign. • Identify any variables or unknowns that the expression requires. • Define any variables, constants, or functions used in the expression. Ensure that each symbol is used for only one thing. That is, don’t use i to refer to the imaginary unit, the index of a summation symbol, and a variable electric current in the same expression. • Indicate if any of symbols have a restricted domain. Indicate if any of symbols have a restricted domain. If the expression expects p to be prime and t to be a real number between 0 and 1, then be sure to say so. The expression at the right can’t be simplified in general, but if the problem it came from required that s is odd and