Question

Teacher asked a question to the students in the class: Find the difference of squares of 55 and 45. Abhinav used an identity and solved the question immediately

a) Which identity did Abhinav use?

b) Solve the above question using the identity?

c) What Value should student learn from
Abhinav?​

Please Solve in copy.​

Answer 1

Answer :

Using Formula (x+a)(x+b) = x

2

+(a+b)x+ab

Writing 55 as 50+5 and 45 as 50−5

⇒ (50+5)(50−5) = 50

2

+[5+(−5)]50+(5)(−5)

= 2500+(0)50−25

= 2475

The answer is 2475