What is obtained by expanding (3a(2a-1))?
Answer and explanation
Correct answer: \(6a^2-3a\)
Using the distributive property, multiply \(3a\) by each term inside the bracket: \(3a\times 2a=6a^2\) and \(3a\times(-1)=-3a\). Therefore, the expression becomes \(6a^2-3a\). Option A is incorrect because it does not use \(a\times a=a^2\). Exam tip: When multiplying terms, multiply the coefficients and also combine the powers of the variables correctly.
Frequently asked questions
What is the correct answer to this question?
\(6a^2-3a\)
Why is this the correct answer?
Using the distributive property, multiply \(3a\) by each term inside the bracket: \(3a\times 2a=6a^2\) and \(3a\times(-1)=-3a\). Therefore, the expression becomes \(6a^2-3a\). Option A is incorrect because it does not use \(a\times a=a^2\). Exam tip: When multiplying terms, multiply the coefficients and also combine the powers of the variables correctly.
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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