Factoring a Cubic Expression: (f) x^(3)-x^(2)y(1)/(3)xy^(2)-(1)/(27)y^(3)
This article will guide you through the process of factoring the cubic expression: (f) x^(3)-x^(2)y(1)/(3)xy^(2)-(1)/(27)y^(3).
Recognizing the Pattern
The given expression exhibits a distinct pattern:
- Descending powers of x: The terms are arranged in descending order of x powers (x³, x², x¹, x⁰).
- Ascending powers of y: The terms are arranged in ascending order of y powers (y⁰, y¹, y², y³).
- Coefficients with specific fractions: The coefficients follow a pattern related to the powers of (1/3) (1, 1/3, 1/9, 1/27).
This pattern suggests that the expression can be factored using the difference of cubes formula:
(a³ - b³) = (a - b)(a² + ab + b²)
Applying the Difference of Cubes Formula
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Identify 'a' and 'b':
- a = x
- b = (1/3)y
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Substitute 'a' and 'b' into the formula:
- (x - (1/3)y) [x² + x(1/3)y + (1/3)²y²]
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Simplify the expression:
- (x - (1/3)y) (x² + (1/3)xy + (1/9)y²)
The Factored Expression
Therefore, the factored form of the given cubic expression is:
(x - (1/3)y) (x² + (1/3)xy + (1/9)y²)