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.

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.

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.

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.

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

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

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 d the sum of c squared and 21 times d. c.5 3 five to the third power or five cubed.