A rectangle has length (l) and breadth (b). If (2l+2b=34) and (l-b=5), what are (l) and (b)?
Answer and explanation
Correct answer: \(l=11,\ b=6\)
Divide the first equation \(2l+2b=34\) by 2 to get \(l+b=17\). Adding this to \(l-b=5\) gives \(2l=22\), so \(l=11\). Substituting into \(l-b=5\), we get \(11-b=5\), hence \(b=6\). Option C is not correct because its difference is 7, not 5. Exam tip: Simplify coefficients first, then use addition or subtraction to eliminate one variable.
Frequently asked questions
What is the correct answer to this question?
\(l=11,\ b=6\)
Why is this the correct answer?
Divide the first equation \(2l+2b=34\) by 2 to get \(l+b=17\). Adding this to \(l-b=5\) gives \(2l=22\), so \(l=11\). Substituting into \(l-b=5\), we get \(11-b=5\), hence \(b=6\). Option C is not correct because its difference is 7, not 5. Exam tip: Simplify coefficients first, then use addition or subtraction to eliminate one variable.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Pair of Linear Equations in Two Variables. Topic: Algebraic methods: Substitution method and Elimination method..
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
