The general term of is
The general term of is
Then the genaral term of the entire expansion is
So the condition is .
Now take all the possibilities for k and l.
Coefficient of x^4 in the product of the expansions (1 + x)^5.(1 - x)^6 is -
A) 5C2
B) ∑(r = 0 to 4) (-1)^r 6Cr . 5C(4 - r)
C) - 5C3
D) 5C4
More than one options may be correct.