Evaluate: (69.3)² - (30.7)²

Solution:

Given, (69.3)² - (30.7)²

Using standard identity: (a² - b²) = (a + b)(a - b)

Here a = 69.3 and b = 30.7

(69.3)² - (30.7)² = (69.3 + 30.7)( 69.3 - 30.7)

= (100)(38.6) = 3860

✦ Try This: Evaluate: (74.3)² - (25.7)²

Given, (74.3)² - (25.7)²

Using standard identity: (a² - b²) = (a + b)(a - b)

(74.3)² - (25.7)² = (74.3 + 25.7)(74.3 - 25.7)

= (100)(48.6) = 4860

☛ Also Check: NCERT Solutions for Class 8 Maths Chapter 9

NCERT Exemplar Class 8 Maths Chapter 7 Problem 86(xvii)

Evaluate: (69.3)² - (30.7)²

Summary:

Evaluating (69.3)² - (30.7)² we get, 3860

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