Write the number of terms in the expansion of 
.
Given:
(1)
(2)
Add both equations;
The even terms; i.e. k=1,3,5,7 & 9 cancel each other
So, we are left with only terms with k=0,2,4,6,8 &10
So total number of terms = 6
1
Write the number of terms in the expansion of .
Given:
(1)
(2)
Add both equations;
The even terms; i.e. k=1,3,5,7 & 9 cancel each other
So, we are left with only terms with k=0,2,4,6,8 &10
So total number of terms = 6