Engineering Board Exam Reviewer · Binomial Theorem · easy

Find the 4th term in the expansion of (x+y)6.

  1. 15x3y3
  2. 20x4y2
  3. 20x3y3
  4. 15x4y2

Answer

C. 20x3y3

Solution

The (r+1)th term is 6rx6-ryr. For the 4th term r=3: 63x3y3=20x3y3.

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