The value of (a + b)² - (a - b)² is
(a)4ab
(b)- 4ab
(c)2a² + 2b²
(d) 2a² - 2b²

Solution:

Correct option is (a)

Given, (a + b)² - (a - b)²

We have standard identities, (a + b)² = a² + 2ab + b² and (a - b)² = a² - 2ab + b²

∴ (a + b)² - (a - b)² = [a² + 2ab + b²] - [a² - 2ab + b²]

= a² + 2ab + b² - a² + 2ab - b²

= 4ab

✦ Try This: The value of (a + b)² - 4ab is (a) (a + b)², (b) a² + b², (c) a² - b², (d) (a - b)²

Correct option is (d)

Given, (a + b)² - 4ab , by using the identity (a + b)² = a² + 2ab + b² we get

= a² + 2ab + b² - 4ab = a² - 2ab + b² = (a - b)²

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

NCERT Exemplar Class 8 Maths Chapter 7 Problem 33

The value of (a + b)² - (a - b)² is (a) 4ab, (b) - 4ab, (c) 2a² + 2b², (d) 2a² - 2b²

Summary:

The value of (a + b)² - (a - b)² is 4ab

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