0 reads0 ratings0 helpful
Which of the following expressions can be factorised directly using the identity for the difference of squares, \(a^2-b^2=(a-b)(a+b)\)?
Advertisement
Answer and explanation
Correct answer: \(25p^2-49q^2\)
\(25p^2-49q^2=(5p)^2-(7q)^2\), so it is a difference of squares and factors as \((5p-7q)(5p+7q)\). B has a sum, while C is a perfect square. Exam tip: check for two squares joined by a minus sign.
Frequently asked questions
What is the correct answer to this question?
\(25p^2-49q^2\)
Why is this the correct answer?
\(25p^2-49q^2=(5p)^2-(7q)^2\), so it is a difference of squares and factors as \((5p-7q)(5p+7q)\). B has a sum, while C is a perfect square. Exam tip: check for two squares joined by a minus sign.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Exploring Algebraic Identities. Topic: Factorisation.
Student feedback
Was this question useful?
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Difficulty
Easy0%
Medium0%
Hard0%
Was the explanation clear?
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
Advertisement