["Understanding the Misconception: Why √120 ≠ 12 – 2√30", "When simplifying square roots, one common error is miscalculating expressions like √120 or assuming relationships such as √120 = 12 – 2√30. This article clarifies the correct mathematical interpretation and explains why that assertion is false.", "### The Correct Value of √120", "First, let's accurately simplify √120:", "[
\n\sqrt{120} = \sqrt{4 \ imes 30} = \sqrt{4} \ imes \sqrt{30} = 2\sqrt{30}
\n]", "So, √120 simplifies to 2√30, not 12 – 2√30.", "### Why the Statement √120 = 12 – 2√30 Is Incorrect", "The expression 12 – 2√30 is a completely different value with no mathematical connection to √120:", "- √120 ≈ 10.95, while
\n- 12 – 2√30 ≈ 12 – 2(5.477) ≈ 12 – 10.954 ≈ 1.046", "These values clearly differ, showing that equating √120 to 12 – 2√30 is mathematically invalid. This confusion often stems from misapplying properties of radicals or misunderstanding simplification rules.", "### Key Rules to Avoid the Mistake", "1. Factor and Simplify Correctly:
\n Break numbers under the square root into perfect squares and remaining radicals:
\n √(a × b) = √a × √b, especially when a is a perfect square.", "2. Do Not Distribute or Rearrange Subtractively:
\n √(x – y) ≠ √x – √y — this property does not apply.", "3. Simplify Fully Before Comparing:
\n Always fully simplify radicals before plugging values into expressions.", "### Proper Simplification Example", "Simplify √120 step-by-step:", "[
\n\sqrt{120} = \sqrt{4 \ imes 30} = \sqrt{4} \cdot \sqrt{30} = 2\sqrt{30}
\n]", "This confirms √120 = 2√30, not 12 – 2√30.", "### Why This Clarification Matters", "Misunderstanding such expressions can impact students learning algebra, trigonometry, and calculus. Accurate radical simplification forms a foundation for solving equations, evaluating limits, and working with irrational numbers.", "In summary, the claim that √120 equals 12 – 2√30 is erroneous. The correct simplification is 2√30. Always simplify radicals properly and avoid invalid algebraic manipulations.", "---", "Keywords for SEO: √120 simplification, correct square root values, how to simplify √120, common math mistakes with radicals, √120 vs 12 – 2√30, full simplification of square roots, mathematical error correction.", "Meta Description:
\nLearn why √120 does not equal 12 – 2√30. Discover the correct simplification steps and key rules to avoid errors when working with square roots."]