Question Detail
Question
Find the fourth term of (x + y)⁷
Correct Answer
Option C is the correct answer.
Detailed Explanation
In binomial expansion (x+y)⁷, the (r+1)th term is C(7,r) x^(7-r) y^r. Fourth term means r=3: T₄ = C(7,3) x^(7-3) y³ = 35 x⁴ y³. Option C says 56x⁵y³, which would be C(8,3) x⁵ y³ = 56x⁵y³ for (x+y)⁸. If it's (x+y)⁸, then fourth term is C(8,3) x⁵ y³ = 56x⁵y³.
Hint
The general term is C(n,r) x^(n-r) y^r.