Evaluate variable expressions involving rational numbers
Evaluating expressions with rational numbers (fractions and decimals) follows the same rules as with integers. Substitute the given value for the variable and use the order of operations to solve.
Lesson 2
Concept
**Example 1: With Decimals** Evaluate 2.5x + 1.2 when x = 3. 1. **Substitute:** 2.5(3) + 1.2 2. **Simplify:** 7.5 + 1.2 3. **Solve:** 8.7 **Example 2: With Fractions** Evaluate (1/2)y - 1/4 when y = 3/2. 1. **Substitute:** (1/2)(3/2) - 1/4 2. **Simplify:** 3/4 - 1/4 3. **Solve:** 2/4 = 1/2
Try it
Practice: Evaluate variable expressions involving rational numbers.