Simplify: (3x + 2y)² - (3x - 2y)²
Solution:
Given, (3x + 2y)² - (3x - 2y)²
Using standard identities: (a + b)² = a² + 2ab + b² and (a - b)² = a² - 2ab + b²
Here, a = 3x and b = 2y
(3x + 2y)² - (3x - 2y)²
= [(3x)² + 2(3x)(2y) + (2y)²] - [(3x)² - 2(3x)(2y) + (2y)²]
= [9x² + 12xy + 4y²] - [9x² - 12xy + 4y²]
= 9x² - 9x² + 12xy + 12xy + 4y² - 4y²
= 24xy
✦ Try This: Simplify: (7p + 4q)² - (7p - 4q)²
Given, Simplify: (7p + 4q)² - (7p - 4q)²
Using standard identities: (a + b)² = a² + 2ab + b² and (a - b)² = a² - 2ab + b²
Here, a = 7p and b = 4q
= [(7p)² + 2(7p)(4q) + (4q)²] - [(7p)² - 2(7p)(4q) + (4q)²]
=49p² + 56pq + 16q² - 49p² + 56pq - 16q²
= 112pq
☛ Also Check: NCERT Solutions for Class 8 Maths Chapter 9
NCERT Exemplar Class 8 Maths Chapter 7 Problem 84(ii)
Simplify: (3x + 2y)² - (3x - 2y)²
Summary:
Simplifying (3x + 2y)² - (3x - 2y)² we get, 24xy
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