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  1. Chapter 6 Class 8 Squares and Square Roots
  2. Serial order wise

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 Example 1 Find the square of the following numbers without actual multiplication. (ii) 42 We know that 42 = 40 + 2 Now, 422 = 42 × 42 = (40 + 2) × (40 + 2) = 40 × (40 + 2) + 2 × (40 + 2) = 40 × 40 + (40 × 2) + (2 × 40) + 2 × 2 = 1600 + 80 + 80 + 4 = 1764

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.