Vocabulary Variable Constant Algebraic Expression Evaluate

Vocabulary A variable is a letter or symbol that represents a quantity that can change. A constant is a quantity that does not change. Inflation Table: $1$7 $2$14 $3$21 $ p$ p x 7 In the table what are your variables and what are you constants?

An algebraic expression contains one or more variables and may contain operation symbols. So p  7 is an algebraic expression. Algebraic Expressions NOT Algebraic Expressions y85 ÷ 5 35  w + z  5 To evaluate an algebraic expression, substitute a number for the variable and then find the value.

You can write multiplication and division expressions without using the symbols  and . Instead of... You can write... x  3 x  3 35 ÷ y x(3) 3x3x 35 y When you are multiplying a number times a variable, the number is written first. Write “3x” not “x3.” Read 3x as “three x.” Writing Math

Evaluate the expression to find the missing values in the table. Additional Example 1A: Evaluating Algebraic Expressions Substitute for y in 5  y. y 5  y y = 16; 5  16 = 80 y = 27; 5  = y = 35; 5  =

Evaluate the expression to find the missing values in the table. Additional Example 1B: Evaluating Algebraic Expressions z z  z = 20; 20  = 20 z = 45; __  = __ z = 60; __  = __ Substitute for z in z 

Check It Out: Example 1A Evaluate the expression to find the missing values in the table. Substitute for x in x  9. x x  x = 18; 18  9 = 2 x = 36;  9 = x = 54;  9 =