Which expression is obtained by expanding (2x^2(3x-4))?
Answer and explanation
Correct answer: \(6x^3-8x^2\)
Use the distributive property: \(2x^2\times 3x=6x^3\) and \(2x^2\times(-4)=-8x^2\). Therefore, the expanded expression is \(6x^3-8x^2\). In option D, the second term is positive, but multiplication by \(-4\) gives a negative term. Exam tip: while multiplying powers of \(x\), add their exponents; for example, \(x^2\times x=x^3\).
Frequently asked questions
What is the correct answer to this question?
\(6x^3-8x^2\)
Why is this the correct answer?
Use the distributive property: \(2x^2\times 3x=6x^3\) and \(2x^2\times(-4)=-8x^2\). Therefore, the expanded expression is \(6x^3-8x^2\). In option D, the second term is positive, but multiplication by \(-4\) gives a negative term. Exam tip: while multiplying powers of \(x\), add their exponents; for example, \(x^2\times x=x^3\).
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Algebraic expressions.
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