Which of the following expressions is the correct factorisation of the sum of two cubes?
Answer and explanation
Correct answer: \(a^3+b^3=(a+b)(a^2-ab+b^2)\)
The standard identity is \(a^3+b^3=(a+b)(a^2-ab+b^2)\), with a negative middle term. On multiplying, the cross terms cancel and give \(a^3+b^3\). Exam tip: distinguish the signs in sum and difference of cubes.
Frequently asked questions
What is the correct answer to this question?
\(a^3+b^3=(a+b)(a^2-ab+b^2)\)
Why is this the correct answer?
The standard identity is \(a^3+b^3=(a+b)(a^2-ab+b^2)\), with a negative middle term. On multiplying, the cross terms cancel and give \(a^3+b^3\). Exam tip: distinguish the signs in sum and difference of cubes.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Exploring Algebraic Identities. Topic: Algebraic identities.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.