A rectangle has length (3x-2) and breadth (2x+5). What is the expression for its perimeter?
Answer and explanation
Correct answer: \(10x+6\)
The perimeter of a rectangle is \(2(\text{length}+\text{breadth})\). Thus, \(2[(3x-2)+(2x+5)]=2(5x+3)=10x+6\). Hence, the correct expression is \(10x+6\). The expression \(5x+3\) is only the sum of the length and breadth, not the perimeter. Exam tip: A perimeter includes all four sides, so multiply the sum of length and breadth by 2.
Frequently asked questions
What is the correct answer to this question?
\(10x+6\)
Why is this the correct answer?
The perimeter of a rectangle is \(2(\text{length}+\text{breadth})\). Thus, \(2[(3x-2)+(2x+5)]=2(5x+3)=10x+6\). Hence, the correct expression is \(10x+6\). The expression \(5x+3\) is only the sum of the length and breadth, not the perimeter. Exam tip: A perimeter includes all four sides, so multiply the sum of length and breadth by 2.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Algebraic expressions.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
