Find the value of a, if pqa = (3p + q)² - (3p - q)²

Solution:

Given, pqa = (3p + q)² - (3p - q)²

⇒ pqa = [(3p)² + 2(3p)(q) + q²] - [(3p)² - 2(3p)(q) + q²]

⇒ pqa = (3p)² + 2(3p)(q) + q² - (3p)² + 2(3p)(q) - q²

⇒ pqa = 6pq + 6pq = 12pq

⇒ a = 12

✦ Try This: Find the value of a, if xya = (5x + y)² - (5x - y)²

Given, xya = (5x + y)² - (5x - y)²

⇒ xya = [(5x)² + 2(5x)(y) + y²] - [(5x)² - 2(5x)(y) + y²]

⇒ xya = (5x)² + 10xy + y² - (5x)² + 10xy - y²

⇒ xya = 20xy

⇒ a = 20

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

NCERT Exemplar Class 8 Maths Chapter 7 Problem 114(iii)

Find the value of a, if pqa = (3p + q)² - (3p - q)²

Summary:

The value of a, if pqa = (3p + q)² - (3p - q)² is 12

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