Evaluating an Algebraic Expression With Addition or Subtraction

An algebraic expression is a combination of letters, numbers and operations without an equation or inequality sign. Here, letters represent the variables and operations can be addition, subtraction, multiplication and division.

Evaluating an algebraic expression means replacing the letters or variables in the expression with the values or numbers given.

In this lesson, we are evaluating algebraic expressions involving addition or subtraction operations only.

Evaluate the algebraic expression 12 + x; for x = 2

Solution

Step 1:

To evaluate the given algebraic expression, we replace x with 2 in the expression.

12 + x = 12 + 2 = 14

Step 2:

So, for x = 2, 12 + x = 14

Evaluate the algebraic expression x − 3; for x = 11

Solution

Step 1:

To evaluate the given algebraic expression, we replace x with 11 in the expression.

x − 3 = 11 − 3 = 8

Step 2:

So, for x = 11, x − 3 = 8

Evaluate the algebraic expression y + 5; for y = 9

Solution

Step 1:

To evaluate the given algebraic expression, we replace y with 9 in the expression.

y + 5 = 9 + 5 = 14

Step 2:

So, for y = 9, y + 5 = 14