What is obtained after simplifying (5(x+2)-2(x-1))?
Answer and explanation
Correct answer: \(3x+12\)
On expanding the brackets, \(5(x+2)-2(x-1)=5x+10-2x+2\). Multiplying \(-2\) by both terms in \((x-1)\) gives \(-2x+2\). Combining like terms gives \(5x-2x+10+2=3x+12\). The option \(3x+8\) may result from using the wrong sign for the constant term in \(-2(x-1)\). Exam tip: when a negative coefficient is outside a bracket, distribute it carefully to every term inside.
Frequently asked questions
What is the correct answer to this question?
\(3x+12\)
Why is this the correct answer?
On expanding the brackets, \(5(x+2)-2(x-1)=5x+10-2x+2\). Multiplying \(-2\) by both terms in \((x-1)\) gives \(-2x+2\). Combining like terms gives \(5x-2x+10+2=3x+12\). The option \(3x+8\) may result from using the wrong sign for the constant term in \(-2(x-1)\). Exam tip: when a negative coefficient is outside a bracket, distribute it carefully to every term inside.
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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