Algebraic Expressions Intro to Algebra

Numerical Expression A numerical expression represents one value and can contain one or more numbers and operations is a numerical expression. It represents the value 9.

Example Which numerical expressions represent a value of 21? a)9 + 24b) c) d) 7 x 3e) x f) 160 ÷ 8

What if they are not numbers? 7 + x 4y – y ÷ 2

Variables A variable is a symbol that can represent different values. We can substitute numbers in for variables to give the expression a value.

A Number next to a Variable What does it mean when a number is written next to a variable? 4x it means to multiply. 4x means 4 times x.

Examples

Evaluating more expressions 1.p + 11 – q (when q = 16, p = 32) 2.1 ÷ x · y (when y = 4, x = 1) b · c (when b = 2, c = 3)

Algebraic Expression An algebraic expression contains variables, numbers and operations. The value of an algebraic expression can change.

Parts of an Algebraic Expression Terms – A term can be a constant, a variable, or a number with a variable. Terms are separated by either a + or a – sign. Coefficient – In a single term containing a number and a variable, the number in front of the variable is called the coefficient.

Creating Algebraic Expressions Create an algebraic expression to represent the following statements more than a number less than a number.

Remember… Does order matter in addition and/or subtraction? Subtraction only

A word to be careful with… Less than Order is opposite

Create an Algebraic Expression 1.Andy had 14 pencils, but then he lost some. 2. Jake had a number of baseball cards, and then he got 24 more. 3. Diane reduced the number of calories she ate by 50.