Problem
Simplify: √72
📝Step-by-Step Solution
Find perfect square factors
Look for the largest perfect square that divides 72. Perfect squares: 1, 4, 9, 16, 25, 36...
Factor 72
72 = 36 × 2. We use 36 because it's the largest perfect square factor of 72.
Apply the square root property
Use √(ab) = √a × √b to split the radical: √72 = √(36 × 2) = √36 × √2
Simplify the perfect square
√36 = 6 (because 6 × 6 = 36)
Write the final answer
√72 = 6√2
Verify (optional)
(6√2)² = 36 × 2 = 72 ✓
✅Final Answer
6√2
To simplify a square root: (1) Find the largest perfect square factor, (2) Rewrite as product of that perfect square and remaining factor, (3) Take the square root of the perfect square, (4) Leave the non-perfect-square under the radical. Alternative method: Factor into primes: 72 = 2³ × 3² = (2 × 3)² × 2 = 36 × 2.
Ready to Practice Square Roots?
Generate a personalized practice test with MathQuizily. Get instant PDF downloads with answer keys.
Learn more about Square Roots
This worked example is part of the broader square roots guide. Review the method, practice related skills, and create a printable assessment when you are ready.
Open the Square Roots guide