1. 1.1 Variables and Expressions In the algebraic expression 4s, the letter s is called a variable. In algebra, variables are symbols used to represent unspecified numbers or values. Any letter may be used as a variable.

2. Writing Mathematical Expressions An algebraic expression consists of one or more numbers and variables along with one ore more arithmetic operations. Examples: In each expression, the quantities being multiplied are called factors, and the result is called the product.

3. Write Algebraic Expressions Write an algebraic expression for each verbal expression. a.Eight more than a number n. b.7 less than the product of 4 and a number x. c.One third of the size of the original area a.

4. Powers An expression like x n is called a power and is read “x to the nth power.” The variable x is called the base, and n is called the exponent. The exponent indicates the number f times the base is used as a factor.

5. Write Algebraic expressions with Powers Write each expression algebraically. a.The product of 7 and m to the fifth power. 7m 5 b.The difference of 4 and x squared. 4 – x 2

6. Evaluate Powers To evaluate an expression means to find its value. Evaluate each expression. a.2 6 b.4 3

7. Write Verbal Expressions Write a verbal expression for each algebraic expression. a.4m 3 the product of 4 and m to the third power. b.c 2 + 21d the sum of c squared and 21 times d. c.5 3 five to the third power or five cubed.