Expanding (2x + 3y)³ - (2x - 3y)³
This expression involves the difference of two cubes, a common pattern in algebra. We can use a specific formula to simplify the expression:
Formula: a³ - b³ = (a - b)(a² + ab + b²)
Applying the formula to our expression:
- Let a = 2x + 3y
- Let b = 2x - 3y
Now, we can substitute these values into the formula:
[(2x + 3y) - (2x - 3y)][(2x + 3y)² + (2x + 3y)(2x - 3y) + (2x - 3y)²]
Simplifying:
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Simplify the first factor: (2x + 3y) - (2x - 3y) = 6y
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Expand the second factor:
- (2x + 3y)² = 4x² + 12xy + 9y²
- (2x + 3y)(2x - 3y) = 4x² - 9y²
- (2x - 3y)² = 4x² - 12xy + 9y²
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Combine the terms: 6y [4x² + 12xy + 9y² + 4x² - 9y² + 4x² - 12xy + 9y²]
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Simplify: 6y [12x² + 9y²]
Final answer: 36x²y + 54y³
Therefore, the expanded form of (2x + 3y)³ - (2x - 3y)³ is 36x²y + 54y³.