The area of a rectangle whose sides are (2x - 7) and (2x + 7) is
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 4x2 - 49 square units
The area of a rectangle is length × breadth. Here the two sides are a sum and a difference of the same two terms, so the identity \((a-b)(a+b)=a^2-b^2\) gives the product at once, with \(a=2x\) and \(b=7\).
Area \(=(2x-7)(2x+7)\)
\(=(2x)^2-7^2=4x^2-49\) square units