Verify that (3x + 5y)² - 30xy = 9x² + 25y²

Solution:

L.H.S = (3x + 5y)² - 30xy

Using identity: (a + b)² = a² + 2ab + b²

= (3x)² + (2 × 3x × 5y) + (5y)² - 30xy

= 9x² + 30xy + 25y² - 30xy

= 9x² + 25y²

∴ L.H.S = R.H.S

✦ Try This: Verify that: (2a - 3b)² - 6ab = 4a² + 9b²

L.H.S = (2a - 3b)² - 6ab

Using identity: (a - b)² = a² - 2ab + b²

= (2a)² - (2 × 2a × 3b) + (3b)² - 6ab = R.H.S.

∴ L.H.S = R.H.S

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

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NCERT Exemplar Class 8 Maths Chapter 7 Sample Problem 14

Verify that (3x + 5y)² - 30xy = 9x² + 25y²

Summary:

(3x + 5y)² - 30xy = 9x² + 25y² holds good

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