Choose the correct expansion of the identity ( (x-y)^2 ).
Answer and explanation
Correct answer: \(x^2-2xy+y^2\)
Expanding \((x-y)^2=(x-y)(x-y)\) gives \(x^2-xy-xy+y^2=x^2-2xy+y^2\). Therefore, option C is correct. Option A is the expansion of \((x+y)^2\), while option B equals \((x-y)(x+y)\). Exam tip: in a squared binomial, the middle term is twice the product of the terms; here it is \(-2xy\) because of the minus sign.
Frequently asked questions
What is the correct answer to this question?
\(x^2-2xy+y^2\)
Why is this the correct answer?
Expanding \((x-y)^2=(x-y)(x-y)\) gives \(x^2-xy-xy+y^2=x^2-2xy+y^2\). Therefore, option C is correct. Option A is the expansion of \((x+y)^2\), while option B equals \((x-y)(x+y)\). Exam tip: in a squared binomial, the middle term is twice the product of the terms; here it is \(-2xy\) because of the minus sign.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Exploring Algebraic Identities. Topic: Algebraic identities.
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