2.2.1. Evaluate Algebraic Expressions

Evaluate Algebraic Expressions

To evaluate an algebraic expression means to find the value of the expression when the variable is replaced by a given number. To evaluate an expression, we substitute the given number for the variable in the expression and then simplify the expression using the order of operations.

• When we evaluate an expression, the value varies depending on the value used for the variable.
• i.e. Evaluate x + 7 when: a. x = 3, b. x = 12
  • a. (3) + 7 = 10. b. (12) + 7 = 19.
• You need to be careful when an expression has a variable with an exponent. 2x2 is different from (2x)2
  • 2x2 = 2 * x* x, (2x)2 = 2x * 2x