Question

How many terms are there in the expansion of $(4x+7y{)}^{10}+(4x-7y{)}^{10}$ ?

• A. 5
• B. 6
• C. 11
• D. 22

Answer 1

Answer: (B)

In the given expression $(4x+7y{)}^{10}+(4x-7y{)}^{10}$ both the parts will have 11 terms each and odd terms will be same, but even terms will be equal with opposite sign. So, only terms 1,3,5,7,9 and 11 will remain and terms 2,4,6,8 and 10 will cancel each other.
So, total number of terms = 6.