Last updated at Aug. 31, 2021 by Teachoo

Transcript

Example 1 Find the square of the following numbers without actual multiplication. (i) 39 We know that 39 = 30 + 9 Now, 392 = 39 × 39 = (30 + 9) × (30 + 9) = 30 × (30 + 9) + 9 × (30 + 9) = 30 × 30 + (30 × 9) + (9 × 30) + 9 × 9 = 900 + 270 + 270 + 81 = 1521

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.