Which of the following expressions is the correct form of the identity for the difference of two cubes?
Answer and explanation
Correct answer: \(x^3-y^3=(x-y)(x^2+xy+y^2)\)
The difference of two cubes is \(x^3-y^3=(x-y)(x^2+xy+y^2)\). On multiplying, the middle terms cancel, leaving \(x^3-y^3\). The factor \(x^2-xy+y^2\) is used for the sum of cubes. Exam tip: identify the sign in the outer binomial first.
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What is the correct answer to this question?
\(x^3-y^3=(x-y)(x^2+xy+y^2)\)
Why is this the correct answer?
The difference of two cubes is \(x^3-y^3=(x-y)(x^2+xy+y^2)\). On multiplying, the middle terms cancel, leaving \(x^3-y^3\). The factor \(x^2-xy+y^2\) is used for the sum of cubes. Exam tip: identify the sign in the outer binomial first.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Exploring Algebraic Identities. Topic: Algebraic identities.
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