**Definition of Evaluate an Algebraic Expression**

- The process of replacing the variables in an expression with the numerical values and simplifying it is known as evaluating an algebraic expression.

**More about Evaluating an Algebraic Expression**

- Order of operation is used to evaluate an algebraic expression.

**Example of Evaluating an Algebraic Expression**

- To evaluate the algebraic expression ‘4.5 +
*x*’ for*x*= 3.2, we need to replace*x*with 3.2 and then add.

4.5 +*x*= 4.5 + 3.2

=7.7

**Solved Example on Evaluating an Algebraic Expression**

Evaluate the algebraic expression p + 3q + 2p - 3q, for p = 2 and q = - 5.

Choices:

A. 12

B. 18

C. 3

D. 6

Correct Answer: D

Solution:

Step 1:p + 3q + 2p - 3q [Original expression.]

Step 2:= (p + 2p) + (3q - 3q) [Group the like terms together.]

Step 3:= 3p [Solve within the grouping symbols.]

Step 4:= 3 x 2 [Substitute 2 for p.]

Step 5:= 6 [Multiply.]

**Related Terms for Evaluating an Algebraic Expression**

- Algebraic Expression
- Evaluate