Evaluating a Mathematical Expression for an 18-Year-Old Student

To evaluate the expression 4/5 + 2/5 × 1/2, follow these steps:

1. Perform the multiplication first: According to the order of operations (often remembered by the acronym PEMDAS: Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right)), you should first tackle the multiplication part of the expression.
2. The multiplication we have is 2/5 × 1/2. To multiply fractions, you simply multiply the numerators together and the denominators together:
• Numerator: 2 × 1 = 2
• Denominator: 5 × 2 = 10

This gives us:

2/5 × 1/2 = 2/10

3. Simplify the fraction: The fraction 2/10 can be simplified by dividing both the numerator and denominator by 2:
• Numerator: 2 ÷ 2 = 1
• Denominator: 10 ÷ 2 = 5

So, 2/10 = 1/5.

4. Now, substitute back into the original expression:

The expression becomes:

4/5 + 1/5

5. Add the fractions: Since the denominators are the same, we can simply add the numerators:
• Numerator: 4 + 1 = 5
• Denominator remains: 5

This gives us:

4/5 + 1/5 = 5/5

6. Simplify: The fraction 5/5 simplifies to 1.

Final Answer: The value of the expression 4/5 + 2/5 × 1/2 is 1.