If ((a+4)(a-4)) is seen through a rectangle area model, what will be the result?
Answer and explanation
Correct answer: \(a^2-16\)
In the rectangle area model, the side lengths are \(a+4\) and \(a-4\). The partial areas are \(a^2\), \(-4a\), \(4a\), and \(-16\). The terms \(-4a\) and \(4a\) cancel, so the total area is \(a^2-16\). The option \(a^2+16\) misses the negative constant term. Exam tip: use the identity \((x+y)(x-y)=x^2-y^2\).
Frequently asked questions
What is the correct answer to this question?
\(a^2-16\)
Why is this the correct answer?
In the rectangle area model, the side lengths are \(a+4\) and \(a-4\). The partial areas are \(a^2\), \(-4a\), \(4a\), and \(-16\). The terms \(-4a\) and \(4a\) cancel, so the total area is \(a^2-16\). The option \(a^2+16\) misses the negative constant term. Exam tip: use the identity \((x+y)(x-y)=x^2-y^2\).
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Exploring Algebraic Identities. Topic: Visual models of identities.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
